Author name code: parker
ADS astronomy entries on 2022-09-14
author:"Parker, Eugene N."
------------------------------------------------------------------------  

Title: Exploring the innermost solar atmosphere
Authors: Parker, Eugene N.
Bibcode: 2020NatAs...4...19P
Altcode: 2019NatAs.tmp....6P
  The Parker Solar Probe spacecraft completed the first two of its 24
  scheduled orbits around the Sun on 18 June 2019, making history by
  flying halfway between Mercury and the Sun.

Title: The FIELDS Instrument Suite for Solar Probe Plus. Measuring
    the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence,
    and Radio Signatures of Solar Transients
Authors: Bale, S. D.; Goetz, K.; Harvey, P. R.; Turin, P.; Bonnell,
   J. W.; Dudok de Wit, T.; Ergun, R. E.; MacDowall, R. J.; Pulupa,
   M.; Andre, M.; Bolton, M.; Bougeret, J. -L.; Bowen, T. A.; Burgess,
   D.; Cattell, C. A.; Chandran, B. D. G.; Chaston, C. C.; Chen,
   C. H. K.; Choi, M. K.; Connerney, J. E.; Cranmer, S.; Diaz-Aguado, M.;
   Donakowski, W.; Drake, J. F.; Farrell, W. M.; Fergeau, P.; Fermin, J.;
   Fischer, J.; Fox, N.; Glaser, D.; Goldstein, M.; Gordon, D.; Hanson,
   E.; Harris, S. E.; Hayes, L. M.; Hinze, J. J.; Hollweg, J. V.; Horbury,
   T. S.; Howard, R. A.; Hoxie, V.; Jannet, G.; Karlsson, M.; Kasper,
   J. C.; Kellogg, P. J.; Kien, M.; Klimchuk, J. A.; Krasnoselskikh,
   V. V.; Krucker, S.; Lynch, J. J.; Maksimovic, M.; Malaspina, D. M.;
   Marker, S.; Martin, P.; Martinez-Oliveros, J.; McCauley, J.; McComas,
   D. J.; McDonald, T.; Meyer-Vernet, N.; Moncuquet, M.; Monson, S. J.;
   Mozer, F. S.; Murphy, S. D.; Odom, J.; Oliverson, R.; Olson, J.;
   Parker, E. N.; Pankow, D.; Phan, T.; Quataert, E.; Quinn, T.; Ruplin,
   S. W.; Salem, C.; Seitz, D.; Sheppard, D. A.; Siy, A.; Stevens, K.;
   Summers, D.; Szabo, A.; Timofeeva, M.; Vaivads, A.; Velli, M.; Yehle,
   A.; Werthimer, D.; Wygant, J. R.
Bibcode: 2016SSRv..204...49B
Altcode: 2016SSRv..tmp...16B
  NASA's Solar Probe Plus (SPP) mission will make the first in situ
  measurements of the solar corona and the birthplace of the solar
  wind. The FIELDS instrument suite on SPP will make direct measurements
  of electric and magnetic fields, the properties of in situ plasma waves,
  electron density and temperature profiles, and interplanetary radio
  emissions, amongst other things. Here, we describe the scientific
  objectives targeted by the SPP/FIELDS instrument, the instrument
  design itself, and the instrument concept of operations and planned
  data products.

Title: Fundamental Concepts Associated with Magnetic Reconnection
Authors: Gonzalez, W. D.; Parker, E. N.; Mozer, F. S.; Vasyliūnas,
   V. M.; Pritchett, P. L.; Karimabadi, H.; Cassak, P. A.; Scudder,
   J. D.; Yamada, M.; Kulsrud, R. M.; Koga, D.
Bibcode: 2016ASSL..427....1G
Altcode:
  The chapter starts with a discussion about the importance of the concept
  of magnetic field lines in space plasmas and magnetic reconnection,
  followed by presentations on: (a) the meaning and validity of
  empirical constructs related with magnetic reconnection research,
  such as: "moving" magnetic field lines, "frozen-in" condition and
  "diffusion region" of reconnection; and (b) experimental evidence of the
  diffusion region and related energetics. Next, aims to link external
  (MHD) with internal (non-MHD) regions of reconnection are discussed
  in association with the so-called "Axford conjecture", followed by
  short presentations on: (a) global equilibria in reconnection; and (b)
  the role of the separatrices in global aspects of reconnection. In the
  last section, we present additional discussion about the concept of
  "diffusion region" and about the two fundamental questions associated
  with magnetic reconnection reviewed in this chapter.

Title: Rapid Reconnection and Field Line Topology
Authors: Parker, E. N.; Rappazzo, A. F.
Bibcode: 2016ASSL..427..181P
Altcode:
  Rapid reconnection of magnetic fields arises where the magnetic
  stresses push the plasma and field so as to increase the field
  gradient without limit. The intent of the present writing is to show
  the larger topological context in which this commonly occurs. Consider
  an interlaced field line topology as commonly occurs in the bipolar
  magnetic regions on the Sun. A simple model is constructed starting
  with a strong uniform magnetic field B <SUB>0</SUB> in the z-direction
  through an infinitely conducting fluid from the end plate z = 0 to z =
  L with the field lines tied at both end plates. Field line interlacing
  is introduced by smooth continuous random turbulent mixing of the
  footpoints at the end plates. This configuration is well suited to be
  modeled with the reduced magnetohydrodynamic (MHD) equations, with
  the equilibria given by the solutions of the 2D vorticity equation
  in this case. The set of continuous solutions to the "vorticity"
  equation have greatly restricted topologies, so almost all interlaced
  field topologies do not have continuous solutions. That infinite set
  represents the "weak" solutions of the vorticity equation, wherein
  there are surfaces of tangential discontinuity (current sheets) in the
  field dividing regions of smooth continuous field. It follows then
  that current sheets are to be found throughout interlaced fields,
  providing potential sites for rapid reconnection. That is to say,
  rapid reconnection and nanoflaring are expected throughout the bipolar
  magnetic fields in the solar corona, providing substantial heating to
  the ambient gas. Numerical simulations provide a direct illustration of
  the process, showing that current sheets thin on fast ideal Alfvén
  timescales down to the smallest numerically resolved scales. The
  asymmetric structure of the equilibria and the interlacing threshold
  for the onset of singularities are discussed. Current sheet formation
  and dynamics are further analyzed with dissipative and ideal numerical
  simulations.

Title: Magnetic Reconnection
Authors: Gonzalez, Walter; Parker, Eugene
Bibcode: 2016ASSL..427.....G
Altcode:
  No abstract at ADS

Title: Prospects and Limitations of Chemical and Isotopic Groundwater
    Monitoring to Assess the Potential Environmental Impacts of
    Unconventional Oil and Gas Development
Authors: Mayer, B.; Humez, P.; Becker, V.; Nightingale, M.; Ing,
   J.; Kingston, A.; Clarkson, C.; Cahill, A.; Parker, E.; Cherry, J.;
   Millot, R.; Kloppmann, W.; Osadetz, K.; Lawton, D.
Bibcode: 2015PrEPS..13..320M
Altcode:
  No abstract at ADS

Title: Reminiscing my sixty year pursuit of the physics of the Sun
    and the Galaxy
Authors: Parker, Eugene N.
Bibcode: 2014RAA....14....1P
Altcode:
  Reminiscing begins with childhood and passes on to student days through
  graduate school and the first real contact with research. Then early
  academic positions and stumbling efforts to pursue my ideas. The
  first significant progress came as a research associate with
  Prof. W. M. Elsasser at the University of Utah, beginning with
  an introduction to magnetohydrodynamics and the generation of the
  geomagnetic field through induction in the liquid metal core of Earth. A
  move to the University of Chicago to work with Prof. J. A. Simpson,
  on the implications of cosmic ray variations and interplanetary
  magnetic fields, led to the theory of coronal expansion and the solar
  wind and then to exploring the dynamical effects of cosmic rays on
  the galactic magnetic field. Spontaneous current sheets and intrinsic
  rapid reconnection in interlaced magnetic field line topologies were the
  next big project, leading up to retirement. Finally, it is a pleasure
  to recall my many associates, whose fresh thinking helped stimulate
  the daily research activities.

Title: Current Sheets Formation in Tangled Coronal Magnetic Fields
Authors: Rappazzo, A. F.; Parker, E. N.
Bibcode: 2013ApJ...773L...2R
Altcode: 2013arXiv1306.6634R
  We investigate the dynamical evolution of magnetic fields in closed
  regions of solar and stellar coronae. To understand under which
  conditions current sheets form, we examine dissipative and ideal reduced
  magnetohydrodynamic models in Cartesian geometry, where two magnetic
  field components are present: the strong guide field B <SUB>0</SUB>,
  extended along the axial direction, and the dynamical orthogonal
  field b. Magnetic field lines thread the system along the axial
  direction that spans the length L and are line-tied at the top and
  bottom plates. The magnetic field b initially has only large scales,
  with its gradient (current) length scale of the order of l<SUB> b
  </SUB>. We identify the magnetic intensity threshold b/B <SUB>0</SUB>
  ~ l<SUB> b </SUB>/L. For values of b below this threshold, field-line
  tension inhibits the formation of current sheets, while above the
  threshold they form quickly on fast ideal timescales. In the ideal case,
  above the magnetic threshold, we show that current sheets thickness
  decreases in time until it becomes smaller than the grid resolution,
  with the analyticity strip width δ decreasing at least exponentially,
  after which the simulations become underresolved.

Title: Field Line Topology and Rapid Reconnection
Authors: Parker, Eugene N.
Bibcode: 2012ASSP...33....3P
Altcode: 2012msdp.book....3P
  Consider a magnetic field extending through an infinitely conducting
  fluid between end plates z = 0, z = L, with arbitrary interlacing of
  the field lines throughout. The field is fixed in both endplates and
  is allowed to relax to an equilibrium described by the force-free
  equilibrium equation ∇ ×B = αB. The divergence of this field
  equation yields ∇ ṡα = 0, requiring that the torsion coefficient α
  be constant along each individual field line, and showing that the field
  lines represent a family of real characteristics of the equilibrium
  field equation. So the field line topology plays a direct role in
  determining the nature of the equilibrium field. For an arbitrarily
  prescribed interlacing field line topology a continuous field generally
  cannot provide an α that is constant along field lines. Yet with
  the field fixed at both ends it is obvious that every topology has
  an equilibrium. So there must be a mathematical solution to the field
  equation for each and every topology. This dilemma is resolved by the
  fact that the field lines represent a family of real characteristics,
  so that surfaces of discontinuity (current sheets) can form along
  the flux surfaces. In almost all field line topologies, then, the
  continuous field is cut up by surfaces of tangential discontinuity
  between regions of continuous field.

Title: The Dynamics of the Heliosphere from 1961 TO Voyagers i and
    II in 2011
Authors: Parker, E. N.
Bibcode: 2011AGUFMSH13C..02P
Altcode:
  The first MHD models of the heliosphere were produced in 1961,
  illustrating the theoretical shape of the heliosphere in the two
  extremes of an interstellar wind without interstellar magnetic
  field and an interstellar magnetic field without a wind. The lack of
  information on the density and velocity of the solar wind, and on the
  interstellar wind and magnetic field, precluded any real estimate of
  the dimensions of the heliosphere at that time. The plasma detector
  on the Mariner II voyage to Venus in 1962 brought the realities into
  focus, measuring wind densities of 5 ions/cc and velocities of 300 - 700
  km/sec. The subsequent exploration of the solar wind has filled in the
  picture in considerable detail. Most recently, Voyagers I and II have
  determined the dimensions of the heliosphere, as well as suggesting
  unanticipated dynamical effects in the heliosheath. For instance,
  rapid reconnection of the magnetic sector structure into separate
  magnetic bubbles is predicted. Then the curious 4 AU region of vanishing
  radial wind velocity requires explanation. We have also learned that
  the anomalous cosmic rays are not accelerated in the terminal shock,
  at least in the regions penetrated by the Voyagers. So there is much
  yet to be understood, much like the situation in 1961 fifty years ago.

Title: Kinetic and Hydrodynamic Representations of Coronal Expansion
    and The Solar Wind
Authors: Parker, E. N.
Bibcode: 2010AIPC.1216....3P
Altcode:
  We consider the Lemaire-Scherer construction of the supersonic solar
  wind as the kinetic escape of a collisionless (scatter-free) plasma
  from an exosphere near the Sun. The radial electric field enforces
  equality of the electron and ion densities and also equality of
  the electron and ion fluxes. Consequently, the electrons form an
  electrostatically confined atmosphere with the temperature declining
  outward only slowly from the exosphere and becoming the work horse
  that lifts and accelerates the ions to supersonic velocity.

Title: Extraterrestrial Amino Acids in the Almahata Sitta Meteorite
Authors: Callahan, Michael; Aubrey, A.; Bada, J. L.; Dworkin, J. P.;
   Elsila, J. E.; Glavin, D. P.; Parker, E.; Jenniskens, P.
Bibcode: 2009DPS....41.0909C
Altcode:
  The recovery of meteorite fragments from the 2008 TC3 asteroid
  impact, collectively named Almahata Sitta, revealed a rare, anomalous
  polymict ureilite containing large carbonaceous grains (Jenniskens et
  al. 2009). Here we report the first amino acid analysis of a meteorite
  from an F-type asteroid as part of the Almahata Sitta meteorite sample
  analysis consortium. A single fragment (piece #4, 1.2 grams) was crushed
  to a powder, and separate 0.1 g aliquots of the same meteorite were
  carried through identical hot-water extraction, acid hydrolysis and
  desalting procedures at NASA Goddard Space Flight Center and the Scripps
  Institution of Oceanography. The o-phthaldialdehyde/N-acetyl-L-cysteine
  amino acid derivatives in the extracts were analyzed by high performance
  liquid chromatography with UV fluorescence detection and time-of-flight
  mass spectrometry. Analyses of the meteorite extracts revealed a complex
  distribution of two- to six-carbon aliphatic amino acids with abundances
  ranging from 0.5 to 69 parts-per-billion (ppb). Glycine was the most
  abundant amino acid detected, however, since this protein amino acid
  is a common terrestrial contaminant, we are currently unable to rule
  out at least a partial terrestrial source. However, the D/L ratio
  of alanine in the meteorite was racemic, suggesting that very little
  terrestrial amino acid contamination. Several non-protein amino acids
  that are rare in the biosphere were also identified in the meteorite
  above background levels including D,L-4-amino-2-methybutyric acid
  (65 ± 8 ppb), D-isovaline (1.3 ± 0.1 ppb), L-isovaline (1.4 ± 0.1
  ppb), and α-aminoisobutryic acid (7.1 ± 5.8 ppb). The abundance of
  isovaline and AIB are 1000 times lower than the abundances found in
  the CM2 meteorite Murchison while D,L-4-amino-2-methybutyric acid is
  similar. The very low amino acid abundances and the presence of several
  amino acid decomposition products including methylamine, ethylamine,
  and isopropylamine are consistent with extensive thermal alteration
  of organic compounds on the parent asteroid.

Title: Exploration of amino acid biomarkers in polar ice with the
    Mars Organic Analyzer
Authors: Jayarajah, C.; Botta, O.; Aubrey, A.; Parker, E.; Bada, J.;
   Mathies, R.
Bibcode: 2009AGUSM.P11A..08J
Altcode:
  A portable microfabricated capillary electrophoresis (CE) system
  named the Mars Organic Analyzer (MOA) has been developed to analyze
  fluorescently-labeled biomarkers including amino acids, amines,
  nucleobases, and amino sugars with the goal of life detection on Mars
  (1,2). This technology has also been shown to be effective in screening
  the formation of biogenic amines during fermentation (3). The MOA is
  a part of the Urey instrument package that has been selected for the
  2016 European ExoMars mission by ESA. The identification of recent gully
  erosion sites, observations of ice on and beneath the surface of Mars,
  and the discovery of large reservoirs of sub-surface ice on Mars point
  to water-ice as an important target for astrobiological analyses. In
  addition, the ice samples on the Moon, Mercury, Europa and Enceladus are
  of interest due to the possibility that they may contain information
  on biogenic material relevant to the evolution of life. We explore
  here the use of the MOA instrument for the analysis of amino acids in
  polar ice samples. The amino acids valine, alanine/serine, glycine,
  glutamic acid, and aspartic acid were found in the parts-per-billion
  range from Greenland ice-core samples. Chiral analysis of these samples
  yielded D/L ratios of 0.51/0.09 for alanine/serine and 0.14/0.06 for
  aspartic acid. Individual amino acids in the parts-per-trillion range
  were found in Antarctic ice samples collected from the surface of a
  meteorite collection area. The distinct amino acid and amine content
  of these samples indicates that further biomarker characterization of
  ice samples as a function of sampling location, depth, and structural
  features will be highly informative. The rapid sensitive analysis
  capabilities demonstrated here establish the feasibility of using
  the MOA to analyze the biomarker content of ice samples in planetary
  exploration. 1. Skelley, A. M.; Scherer, J. R.; Aubrey, A. D.; Grover,
  W. H.; Ivester, R. H. C., Ehrenfreund, P.; Grunthaner, F. J.; Bada,
  J. L.; Mathies, R. A. PNAS, 2005, 192, 1041. 2. Skelley, A. M.,
  Cleaves, H. J., Jayarajah, C. N., Bada, J. L. and Mathies, R. A.,
  Astrobiology 2006, 6, 824. 3. Jayarajah, C.N., Skelley, A.M., Fortner,
  A.D., and Mathies, R.A., Anal. Chem. 2007, 79, 21, 8162.

Title: Hydrodynamics, magnetohydrodynamics, and astrophysical plasmas
Authors: Parker, E. N.
Bibcode: 2009cwse.conf...23P
Altcode:
  No abstract at ADS

Title: Solar Magnetism: The State of Our Knowledge and Ignorance
Authors: Parker, E. N.
Bibcode: 2009SSRv..144...15P
Altcode: 2008SSRv..tmp..170P
  We review some longstanding scientific mysteries related to solar
  magnetism, with final attention to the mystery of the “turbulent
  diffusion” essential for the theoretical α ω-dynamo that is
  believed to be the source of the magnetic fields of the Sun. Fundamental
  difficulties with the concept of turbulent diffusion of magnetic fields
  suggest that the solar dynamo problem needs to be reformulated. An
  alternative dynamo model is proposed, but it remains to be shown that
  the model can provide the quantitative aspects of the cyclic magnetic
  fields of the Sun.

Title: Solar Magnetism: The State of Our Knowledge and Ignorance
Authors: Parker, E. N.
Bibcode: 2009odsm.book...15P
Altcode:
  We review some longstanding scientific mysteries related to solar
  magnetism, with final attention to the mystery of the "turbulent
  diffusion" essential for the theoretical α ω-dynamo that is believed
  to be the source of the magnetic fields of the Sun. Fundamental
  difficulties with the concept of turbulent diffusion of magnetic fields
  suggest that the solar dynamo problem needs to be reformulated. An
  alternative dynamo model is proposed, but it remains to be shown that
  the model can provide the quantitative aspects of the cyclic magnetic
  fields of the Sun.

Title: Minor Planet Observations [705 Apache Point]
Authors: Becker, A.; Babylon, E.; Hollingsworth, T.; Becker, A. C.;
   Puckett, A. W.; Hendrickson, S.; Vasquez, L.; Zumwalt, L.; Burton,
   M.; Dilucchio, H.; Higley, E.; Warnock, L.; Brady, S.; Gablehouse,
   G.; Kintz, K.; Ouellette, A.; Parker, E.; Ratley, L.; Holmes-Perry,
   K.; Hovden, L.; King, C.; Leemhuis, J.; Pascall, R.; Schwebke, J.
Bibcode: 2008MPC..64488...6B
Altcode:
  No abstract at ADS

Title: Ironstone Concretions - Analogs to Martian Hematite Spherules
Authors: Aubrey, A. D.; Parker, E.; Chalmers, J. H.; Lal, D.; Bada,
   J. L.
Bibcode: 2007LPI....38.2053A
Altcode:
  We report herein physical and chemical characterization of a new
  terrestrial analog to the martian "blueberries" found throughout San
  Diego County.

Title: Conversations on Electric and Magnetic Fields in the Cosmos
Authors: Parker, Eugene N.
Bibcode: 2007cemf.book.....P
Altcode:
  No abstract at ADS

Title: Solar Wind
Authors: Parker, E. N.
Bibcode: 2007hste.book...96P
Altcode:
  No abstract at ADS

Title: Interstellar Conditions and Planetary Magnetospheres
Authors: Parker, Eugene N.
Bibcode: 2006ASSL..338...87P
Altcode:
  No abstract at ADS

Title: Heating the Solar X-Ray Corona
Authors: Parker, E. N.
Bibcode: 2005ESASP.596E...1P
Altcode: 2005ccmf.confE...1P
  No abstract at ADS

Title: Principles of Magnetohydrodynamics, with Applications
    to Laboratory and Astrophysical Plasma. By H. GOEDBLOED &amp;
    S. POEDT. Cambridge University Press, 2004. 632 pp. ISBN 0521 623472,
    £80 (hardback); ISBN 0521 626072, £40 (paperback)
Authors: Parker, E. N.
Bibcode: 2004JFM...519..377P
Altcode:
  Available from <A
  href="http://dx.doi.org/10.1017/S0022112004001466">http://dx.doi.org/10.1017/S0022112004001466</A>

Title: New Seafloor Map of the Puerto Rico Trench Helps Assess
    Earthquake and Tsunami Hazards
Authors: ten Brink, Uri; Danforth, William; Polloni, Christopher;
   Andrews, Brian; Llanes, Pilar; Smith, Shepard; Parker, Eugene;
   Uozumi, Toshihiko
Bibcode: 2004EOSTr..85..349T
Altcode: 2004EOSTr..85..349B
  The Puerto Rico Trench, the deepest part of the Atlantic Ocean,
  is located where the North American (NOAM) plate is subducting under
  the Caribbean plate (Figure 1). The trench region may pose significant
  seismic and tsunami hazards to Puerto Rico and the U.S. Virgin Islands,
  where 4 million U.S. citizens reside. Widespread damage in Puerto
  Rico and Hispaniola from an earthquake in 1787 was estimated to be
  the result of a magnitude 8 earthquake north of the islands. A tsunami
  killed 40 people in NW Puerto Rico following a magnitude 7.3 earthquake
  in 1918. Large landslide escarpments have been mapped on the seafloor
  north of Puerto Rico, although their ages are unknown. The Puerto Rico
  Trench is atypical of oceanic trenches. Subduction is highly oblique
  (10°-20°) to the trench axis with a large component of left-lateral
  strike-slip motion. Similar convergence geometry is observed at the
  Challenger Deep in the Mariana Trench, the deepest point on Earth. In
  addition to its extremely deep seafloor, the Puerto Rico Trench is also
  characterized by the most negative free-air gravity anomaly on Earth,
  -380 mGal, located 50 km south of the trench, where water depth is
  7950 m (Figure 2). A tilted carbonate platform provides evidence for
  extreme vertical tectonism in the region. This platform was horizontally
  deposited over Cretaceous to Paleocene arc rocks starting in the Late
  Oligocene. Then, at 3.5 Ma, the carbonate platform was tilted by 4°
  toward the trench over a time period of less than 40 kyr, such that its
  northern edge is at a depth of 4000 m and its reconstructed elevation
  on land in Puerto Rico is at +1300 m (Figures 1 and 2).

Title: The Microworld of the Solar Corona
Authors: Parker, Eugene
Bibcode: 2004APS..APR.Q1003P
Altcode:
  The corona of the Sun, visible during an eclipse of the Sun, has been
  a challenge to physics for more than a century, and, for all the
  scientific progress, the dynamical microstructure of the corona is
  only beginning to be revealed. To begin, there are three distinct
  states of the million degree coronal gas: The weak-field coronal
  hole, and the strong field, X-ray emitting, bipolar magnetic regions,
  and the active corona surrounding the bipolar regions. Their origin
  leads into the microworld of the magnetic fields, with the intense
  magnetic fibrils at the visible surface, the magnetic carpet, and
  the interlaced bipolar field lines, with the associated nanoflares,
  microflares, and flares, and all with internal scales of 100 km or
  less. Unfortunately 100 km is well below the limit of resolution of
  existing telescopes. An essential step forward is the proposed Advanced
  Technology Solar Telescope, a 4m ground based telescope with adaptive
  optics providing resolution down to 50 km, together with rapid cadence,
  high dispersion spectroscopy to follow the action.

Title: Universal Magnetic Reconnection And Coronal Heating
Authors: Parker, E. N.
Bibcode: 2004hell.conf....1P
Altcode:
  No abstract at ADS

Title: Foreword (Dynamic Sun)
Authors: Parker, E. N.
Bibcode: 2003dysu.bookD..15P
Altcode:
  No abstract at ADS

Title: The Advance Solar Telescope and Future Solar Physics
Authors: Parker, E. N.
Bibcode: 2002AAS...200.3401P
Altcode: 2002BAAS...34..690P
  The magnetic activity of the Sun, with its terrestrial outreach,
  is conventionally defined in terms of the larger magnetic features
  on the surface of the Sun, while the evolution of the large
  magnetic features is largely determined by their small-scale fibril
  structure. Unfortunately the individual fibrils can be observed only
  as unresolved bright blobs. Thus their frequent interactions, their
  internal structure, and the associated dynamical flows all remain
  a mystery, which prevents our constructing a definitive dynamical
  theory of the large-scales and of solar activity in general. The
  microscopic world of magnetic fibrils awaits investigation, requiring
  a suitable telescope system with adaptive optics at an excellent site
  so as to provide angular resolution of 0.1" or better on a regular
  basis. The telescope must be of sufficient aperture ( 4m) to carry
  on high resolution, high dispersion spectroscopy at rapid cadence to
  determine the time dependent spatial structure of the gas flows and
  magnetic fields on the smallest possible scales. It will be important
  to follow the rapid evolution of the small flux bundle, or fibril,
  as it first appears through the visible surface somewhere in the
  interior of a supergranule, and then to follow the resulting magnetic
  fibril as it is convected into the boundary downdrafts, and ultimately
  into the junctions of several boundaries. The quiet photosphere,
  the active photosphere, at both low and high latitudes, the umbra
  and penumbra of sunspots of all sizes, the ephemeral active regions,
  the microstructure of all classes of flares, and the microstructure
  of spicules, surges and prominences are obvious immediate targets for
  the high resolution telescope. We cannot anticipate what will be seen,
  but whatever it turns out to be, it will move scientific comprehension
  well ahead of the present limited conjectural state.

Title: A history of the solar wind concept
Authors: Parker, E. N.
Bibcode: 2002css1.book..225P
Altcode:
  No abstract at ADS

Title: A history of early work on the heliospheric magnetic field
Authors: Parker, E. N.
Bibcode: 2001JGR...10615797P
Altcode:
  The idea of a magnetic field in space around Earth began 400 years ago
  with Gilbert's recognition that the magnetic field of Earth extends
  outward into space to form what we now call the magnetosphere. The
  concept of the solar wind and the heliosphere had its first glimmerings
  with the recognition, about 270 years ago, that geomagnetic activity
  is correlated with solar activity. It was suggested about a 100
  years ago that the connection is through solar corpuscular radiation
  with velocities of the order of 10<SUP>3</SUP>km/s. The observed
  acceleration of comet tails indicated the universal nature of solar
  corpuscular radiation, giving rise to the first speculation on the
  existence of the heliosphere. The hydrodynamic expansion of the million
  degree solar corona was then shown to provide the solar wind (solar
  corpuscular radiation), stretching out the magnetic fields of the Sun
  to fill the heliosphere with a spiral magnetic field. The advent of
  the space age soon verified the solar wind and magnetic field with
  direct measurements.

Title: A Critical Review of Sun-Space Physics
Authors: Parker, E. N.
Bibcode: 2001Ap&SS.277....1P
Altcode:
  The Sun and the heliosphere form a single dynamical system, driven by
  the convection in the Sun and the magnetic fields generated by that
  convection. The magnetic fields are the primary channel for producing
  the high temperatures and high velocities that extend outward to form
  the heliosphere. The essential point is that, while the general picture
  seems to be reasonable, several important steps in the process are not
  understood, and several concepts commonly employed in explanation are
  false physics. These scientific gaps should not be forgotten in the
  rush to pursue new and exotic discoveries.

Title: Magnetic reconnection and the lowest energy state
Authors: Parker, E. N.
Bibcode: 2001EP&S...53..411P
Altcode:
  No abstract at ADS

Title: Solar Activity and Classical Physics
Authors: Parker, E. N.
Bibcode: 2001ChJAA...1...99P
Altcode:
  This review of solar physics emphasizes several of the more conspicuous
  scientific puzzles posed by contemporary observational knowledge
  of the magnetic activity of the Sun. The puzzles emphasize how much
  classical physics we have yet to learn from the Sun. The physics of
  solar activity is based on the principles of Newton, Maxwell, Lorentz,
  Boltzmann, et al., along with the principles of radiative transfer. In
  the large, these principles are expressed by magnetohydrodynamics. A
  brief derivation of the magnetohydrodynamic induction and momentum
  equations is provided, with a discussion of popular misconceptions.

Title: The heliosphere as viewed from Earth
Authors: Parker, E. N.
Bibcode: 2001ohnf.conf..481P
Altcode:
  No abstract at ADS

Title: Large-Scale Plasma Dynamics
Authors: Parker, E.
Bibcode: 2000eaa..bookE2217P
Altcode:
  Most of the universe is occupied by gas that is electrically neutral but
  more or less fully ionized, i.e. PLASMA, and permeated by a magnetic
  field B on a large scale L. The plasma, driven by the energy of the
  stars, is in a remarkably active, and often suprathermal, state. The
  coronal mass ejection from the Sun is an example of the active state,
  while the million degree corona of the Sun is an e...

Title: Instability of the Stochastic Galactic Magnetic Field
Authors: Parker, E. N.; Jokipii, J. R.
Bibcode: 2000ApJ...536..331P
Altcode:
  We examine the effects of the stochastic galactic magnetic field on the
  dynamical instability of the interstellar gas and magnetic field. The
  large-scale random walk, or meandering, of the magnetic field exerts
  stresses across the average magnetic field direction, which suppress
  the growth of perturbations having a small wavelength normal to the
  field. The result is that, compared with a nonstochastic initial
  magnetic field, those perturbations, which grow, are significantly
  broadened in the direction normal to the field. Hence, the instability
  in a stochastic magnetic field, such as that observed in our Galaxy,
  should evolve into clouds that are more similar to those that are
  observed than are those found in the absence of the stochastic field.

Title: Solar Flares, the Solar Corona, and Solar Physics
Authors: Parker, E. N.
Bibcode: 2000IAUS..195..455P
Altcode:
  The Sun serves as the local physics laboratory for studying the
  suprathermal activity phenomena of stars. Scrutiny of the Sun has led
  to the discovery of a host of previously unknown physical effects,
  largely within the classical physics of Newton and Maxwell, but
  including quantum mechanics and lepton physics as well.

Title: Application of Shape Memory Alloys to Rock Splitting: A
    Successful Example of Cooperation between Space Research and Industry
Authors: Carosio, S.; Zangani, D.; Parker, E.; Sutherland, I.
Bibcode: 2000ESASP.470...27C
Altcode: 2000aics.conf...27C
  No abstract at ADS

Title: TUTORIAL: Newton, Maxwell, and Magnetospheric Physics
Authors: Parker, E. N.
Bibcode: 2000GMS...118....1P
Altcode: 2000mcs..book....1P
  The goal of magnetospheric physics is to understand the active
  magnetosphere in terms of the principles of Newton and Maxwell. These
  principles include Ampere's law, the Faraday induction equation, and
  the dynamical interplay of the forces between the bulk plasma velocity
  u, the plasma pressures p<SUB>‖</SUB> and p<SUB>⊥</SUB>, and the
  magnetic field B. It turns out, then, that these principles cannot be
  written in terms of the electric current density j and the electric
  field E, to the exclusion of u and B, in any generally useful form,
  indicating that the electric current and field are not the fundamental
  physical quantities sometimes claimed. Thus, the description of the
  active magnetosphere in electrical terms does not directly address
  the dynamics of the magnetosphere. The popular dynamical concepts
  of the electric circuit analog and the active role of the electric
  field E = -u×B/c in the solar wind have not been established from
  Newton and Maxwell, and application to simple problems illustrates
  their restrictions and errors. In contrast, magnetospheric physics
  is making great strides forward using MHD modeling of the large-scale
  dynamical magnetosphere, and this tutorial emphasizes the generality
  of the MHD approach. We review the theoretical basis for the momentum
  equation and the induction equation for the large-scale nonrelativistic
  dynamics of the magnetosphere and ionosphere, showing the general MHD
  character of the contending stresses and momenta.

Title: LOTIS Limits on Prompt Optical Emission from GRBs
Authors: Hartmann, D. H.; Williams, G. G.; Park, H. S.; Ables, E.;
   Band, D. L.; Barthelmy, S. D.; Bionta, R.; Butterworth, P. S.; Cline,
   T. L.; Ferguson, D. H.; Fishman, G. J.; Gehrels, N.; Hurley, K.;
   Kouveliotou, C.; Meegan, C. A.; Ott, L.; Parker, E.; Porrata, R.
Bibcode: 2000sgrb.conf...37H
Altcode:
  No abstract at ADS

Title: SOLSPA Summary Summary and Perspectives
Authors: Parker, E. N.
Bibcode: 2000ESASP.463..263P
Altcode: 2000sctc.proc..263P
  No abstract at ADS

Title: The physics laboratory in the sky
Authors: Parker, E. N.
Bibcode: 1999CSci...77.1445P
Altcode:
  No abstract at ADS

Title: Space Physics Before the Space Age
Authors: Parker, E. N.
Bibcode: 1999ApJ...525C.792P
Altcode: 1999ApJC..525..792P
  No abstract at ADS

Title: The separation of field and fluid in the Sun
Authors: Parker, E. N.; Thyagaraja, A.
Bibcode: 1999SoPh..189...45P
Altcode:
  The magnetic field at the surface of the Sun is confined to widely
  separated small, intense magnetic flux bundles or fibrils with most of
  the gas in a relatively field free state in the interstices. There is
  evidently a systematic field and fluid separation effect in operation,
  overriding the tendency for turbulent mixing of the two phases. It is
  well known that a constantly rotating volume of fluid soon excludes
  any exterior magnetic field. To take the next theoretical step,
  this paper examines the exclusion of magnetic field from a circular
  cylinder with oscillating angular velocity. The result is that the
  field is effectively excluded from any oscillating or tumbling body of
  fluid that maintains coherence over a sufficiently long time. However,
  there is no expectation of such long term coherence in turbulent
  convection in the Sun, suggesting that the observed separation of
  field and fluid does not come about by the exclusion of field from
  convective cells. This leads to the conclusion that the separation
  of fluid and field is a consequence of extraction of fluid from the
  field through buoyancy and reconnection.

Title: LOTIS Search for Early-Time Optical Afterglows: GRB 971227
Authors: Williams, G. G.; Park, H. S.; Ables, E.; Band, D. L.;
   Barthelmy, S. D.; Bionta, R.; Butterworth, P. S.; Cline, T. L.;
   Ferguson, D. H.; Fishman, G. J.; Gehrels, N.; Hartmann, D. H.; Hurley,
   K.; Kouveliotou, C.; Meegan, C. A.; Ott, L.; Parker, E.; Porrata, R.
Bibcode: 1999ApJ...519L..25W
Altcode: 1999astro.ph..2190W
  We report on the very early time search for an optical afterglow
  from GRB 971227 with the Livermore Optical Transient Imaging System
  (LOTIS). LOTIS began imaging the ``original'' BATSE error box of
  GRB 971227 ~14 s after the onset of gamma-ray emission. Continuous
  monitoring of the position throughout the evening yielded a total
  of 499 images (10 s integration). Analysis of these images revealed
  no steady optical afterglow brighter than R=12.3+/-0.2 in any single
  image. Co-addition of the LOTIS images also failed to uncover transient
  optical emission. In particular, assuming a constant early-time
  flux, no optical afterglow brighter than R=14.2+/-0.2 was present
  within the first 1200 s, and no optical afterglow brighter than
  R=15.0+/-0.2 was present in the first 6.0 hr. Follow-up observations
  by other groups revealed a likely X-ray afterglow and a possible
  optical afterglow. Although subsequent deeper observations could
  not confirm a fading source, we show that these transients are not
  inconsistent with our present knowledge of the characteristics of
  gamma-ray burst afterglows. We also demonstrate that with the upgraded
  thermoelectrically cooled CCDs, LOTIS is capable of either detecting
  very early time optical afterglow or placing stringent constraints
  on the relationship between the gamma-ray emission and the longer
  wavelength afterglow in relativistic blast-wave models.

Title: Space physics before the space age
Authors: Parker, E. N.
Bibcode: 1999AIPC..471....3P
Altcode: 1999sowi.conf....3P
  The concept of space and the ponderable dynamical activity in space
  have a long history of development, going back centuries and millenia,
  and what is commonplace today should not be considered apriori obvious,
  however ``obvious'' it may seem now that it has been discovered and
  studied. The development of space physics over the centuries has
  followed close on the heels of the development of physics. With the
  fundamental laws of classical physics well in hand today, present space
  physics research aims at direct discovery of the diverse phenomena
  occurring in space, followed by sufficiently detailed quantitative
  study to understand how the effects follow from the basic principles
  of Newton, Maxwell, Boltzmann, et al. The pursuit of space physics
  often turns up new twists to the ``old'' physics of the terrestrial
  laboratory, made possible by the vastly greater dimensions of space. The
  present review traces the development of physics and its application
  to space physics from classical times to the early years of the space
  age, when direct in situ studies of space became possible.

Title: Solar physics:  Sunny side of global warming
Authors: Parker, E. N.
Bibcode: 1999Natur.399..416P
Altcode:
  No abstract at ADS

Title: It Started with George Ellery Hale
Authors: Parker, E. N.
Bibcode: 1999AAS...194.5703P
Altcode: 1999BAAS...31..915P
  With his invention of the spectroheliograph, showing the structure
  and activity of the surface of the Sun, and with his spectroscopic
  determination of the magnetic character of the sunspot, Hale initiated
  a line of research that has brought us deeper into the mysteries of the
  Sun with each passing decade. The flare is perhaps the most spectacular
  aspect of the activity, along with the more recently discovered coronal
  mass ejection. However, we must not overlook the spectacular revelation,
  by Grotrian, Edlen, and Lyot, that the outer atmosphere of the Sun
  has a temperature of a million or more degrees K, providing both radio
  and X-ray emission. It is all too often forgotten in these heady times
  that, while we have a number of plausible ideas about how things work,
  there is not yet a clear understanding of why a late main sequence
  star should exhibit such effects. Magnetic fields generated by some
  form of MHD dynamo appear to initiate the suprathermal activity in
  all its many forms. The intensely fibril form of the magnetic fields
  seems to be a clue to the nature of the dynamo process, and the first
  observational priority now is to develop a 4m telescope with an adaptive
  optics system that can properly resolve the individual fibrils at the
  visible surface (0.1" or better)to determine their behavior. Indeed
  the nature of the sunspot, the faculae and plages,the microflare,
  etc. all lie at the limits of telescopic resolution. The varying
  brightness of the Sun seems to be a byproduct of the magnetic activity,
  and besides the consequences for the climate at Earth, provides another
  baffling clue to the puzzle. We cannot guess what further marvels will
  be discovered before the puzzle is resolved in hard scientific terms,
  but we may be certain that Hale would have been enchanted, and probably
  leading the charge, were he alive today.

Title: Fifty Years of the Galactic Magnetic Field
Authors: Parker, E. N.
Bibcode: 1999AAS...194.2503P
Altcode: 1999BAAS...31..863P
  Scientific awareness of the galactic magnetic field had its beginning
  in the years 1948 - 1951 with Fermi's work on cosmic rays, and the
  observation of the polarization of dust reddened starlight by Hiltner
  and Hall, and the interpretation of the polarization in terms of
  magnetically aligned dust grains by Spitzer and Tukey and by Davis
  and Greenstein. The field was more or less along the local spiral
  arm, with large fluctuations on scales of 100 pc. Faraday rotation
  measurements indicated a strength of the order of a few microgauss,
  and dynamical considerations on the structure of the gaseous disk of
  the galaxy suggested similar values. By 1966 it was clear that the
  magnetic field and the cosmic ray gas were tied to the interstellar
  gas to form an unstable active tripart dynamical system. The system is
  continually inflated by blast waves from supernovae and particularly by
  the cosmic ray gas from supernovae, which extend lobes of the galactic
  magnetic field outward at speeds of the order of 50 km/sec in both
  directions from the disk of the Galaxy to form the galactic halo. The
  dissipation of shock waves and the dissipation of magnetic field in
  the halo evidently provide the multi-million degree gas responsible
  for the x-ray emission from the halo, best seen from galaxies other
  than our own. The concentration of magnetic field in and along the
  spiral density waves forming the spiral arms strongly suggests that the
  galactic magnetic field represents a progressive dynamo wave. However,
  the dynamo theory of the galactic magnetic field has yet to establish
  the nature of the field dissipation that makes the dynamo possible.

Title: Magnetic Discontinuities from Field Topology
Authors: Parker, E. N.
Bibcode: 1999Ap&SS.264....1P
Altcode: 1998Ap&SS.264....1P
  No abstract at ADS

Title: LOTIS Constraints on Simultaneous and Early Time Optical
    Emission from Gamma-Ray Bursts
Authors: Williams, G. G.; Hartmann, D. H.; Park, H. S.; Ables, E.;
   Bionta, R.; Ott, L.; Parker, E.; Band, D. L.; Barthelmy, S. D.;
   Butterworth, P. S.; Cline, T. L.; Gehrels, N.; Ferguson, D. H.;
   Fishman, G. J.; Meegan, C. A.; Kouveliotou, C.; Hurley, K.
Bibcode: 1998AAS...192.4304W
Altcode: 1998BAAS...30..874W
  LOTIS (Livermore Optical Transient Imaging System) is a gamma-ray burst
  (GRB) optical counterpart search experiment capable of imaging an
  initial GRB error box within 10 s of the start of a burst. This early
  response, often simultaneous with gamma-ray emission, is accomplished
  by utilizing a fully automated rapidly slewing telescope linked to
  the GRB Coordinates Network (GCN). The LOTIS telescope consists of
  four cameras configured in a 2 x 2 array with a total field-of-view
  of 17.4(deg) x 17.4(deg) . Since routine operations began in October
  1996 LOTIS has responded to more than 40 GCN triggers. We will
  report on LOTIS observations which have placed upper limits on the
  ratio of simultaneous optical to gamma-ray flux. A recent upgrade to
  thermoelectric cooled CCDs increased the LOTIS sensitivity to V ~ 15
  (10 s integration) extending the capability of detecting or further
  constraining simultaneous optical activity from GRBs. In addition to
  LOTIS, Super-LOTIS, a fully automated 60 cm reflector with a limiting
  magnitude of V ~ 19 will soon begin a dedicated search for optical
  counterparts of GRBs. Both the upgraded LOTIS system and Super-LOTIS
  will also search for very early time optical afterglow from GRBs.

Title: Super-LOTIS a high-sensitive optical counterpart search
    experiment
Authors: Park, H. S.; Ables, E.; Band, D. L.; Barthelmy, S. D.;
   Bionta, R. M.; Butterworth, P. S.; Cline, T. L.; Ferguson, D. H.;
   Fishman, G. J.; Gehrels, N.; Hartmann, D.; Hurley, K.; Kouveliotou,
   C.; Meegan, C. A.; Ott, L.; Parker, E.; Williams, G. G.
Bibcode: 1998AIPC..428..842P
Altcode: 1998hgrb.symp..842P
  We are constructing a 0.6 meter telescope system to search for
  early time gamma-ray burst (GRB) optical counterparts. Super-LOTIS
  (Super-Livermore Optical Transient Imaging System) is an automated
  telescope system that has a 0.8°×0.8° field-of-view, is sensitive
  to Mv~19 and responds to a burst trigger within 5 min. This telescope
  will record images of the gamma-ray burst coordinates that are given
  by the GCN (GRB Coordinate Network). A measurement of GRB light curves
  at early times will greatly enhance our understanding of GRB physics.

Title: First year results from LOTIS
Authors: Williams, G. G.; Park, H. S.; Ables, E.; Band, D. L.;
   Barthelmy, S. D.; Bionta, R.; Butterworth, P. S.; Cline, T. L.;
   Ferguson, D. H.; Fishman, G. J.; Gehrels, N.; Hartmann, D. H.; Hurley,
   K.; Kouveliotou, C.; Meegan, C. A.; Ott, L.; Parker, E.; Wurtz, R.
Bibcode: 1998AIPC..428..837W
Altcode: 1998hgrb.symp..837W
  LOTIS (Livermore Optical Transient Imaging System) is a gamma-ray burst
  optical counterpart search experiment located near Lawrence Livermore
  National Laboratory in California. The system is linked to the GCN
  (GRB Coordinates Network) real-time coordinate distribution network
  and can respond to a burst trigger in 6-15 seconds. LOTIS has a total
  field-of-view of 17.4°×17.4° with a completeness sensitivity of mv~11
  for a 10 second integration time. Since operations began in October
  1996, LOTIS has responded to over 30 GCN/BATSE GRB triggers. Seven
  of these triggers are considered good events subject to the criteria
  of clear weather conditions, &lt;60 s response time, and &gt;50%
  coverage of the final BATSE 3σ error circle. We discuss results from
  the first year of LOTIS operations with an emphasis on the observations
  and analysis of GRB971006 (BATSE trigger 6414).

Title: The sun: the ultimate challenge to astrophysics
Authors: Parker, E. N.
Bibcode: 1998AdSpR..21..267P
Altcode:
  Among the many exotic astronomical objects available for study, the
  proximity of the Sun provides the principal source of new physics,
  ranging from neutrinos to the mysteries of the magnetohydrodynamic
  activity and to the geological evolution of terrestrial climate. For
  it must be recalled that it is not known why the Sun is compelled by
  the laws of nature to produce something as familiar as the sunspot or
  as unexpected as the year by year variation in irradiance. The next
  decade holds exciting promise of experimental exploration of neutrino
  physics, advanced helioseismic exploration of magnetic fields below the
  photosphere, and high resolution glimpses of the small scale activity
  and magnetic fibril behavior at the visible surface (e.g. SOHO). It
  behooves the solar physics community to represent the productive state
  of affairs to the rest of the astrophysical world, who need the physics
  in their speculations on the nature of their unresolved objects.

Title: LOTIS: A Search for Simultaneous Optical Counterparts of
    Gamma-Ray Bursts
Authors: Williams, G. G.; Hartmann, D. H.; Park, H. S.; Ables, E.;
   Bionta, R.; Ott, L.; Parker, E.; Band, D. L.; Barthelmy, S. D.;
   Butterworth, P. S.; Cline, T. L.; Gehrels, N.; Ferguson, D. H.;
   Fishman, G. J.; Meegan, C. A.; Kouveliotou, C.; Hurley, K.
Bibcode: 1998BAAS...30..762W
Altcode:
  LOTIS (Livermore Optical Transient Imaging System) is a gamma-ray burst
  (GRB) optical counterpart search experiment located near Lawrence
  Livermore National Laboratory in California. The LOTIS telescope
  consists of a 2 x 2 array of cameras mounted on a rapidly slewing
  mount. The system is fully automated and linked to the GRB Coordinates
  Network (GCN). Imaging of an initial GRB error box begins ~ 6--15 s
  after the start of a burst. LOTIS can detect all objects brighter than
  V ~ 11 (10 s integration) within a total field-of-view of 17.4(deg)
  x 17.4(deg) . Since the beginning of routine operations in October
  1996, LOTIS has responded to over 35 GCN triggers. We will report on
  the results from the first year of LOTIS operations with an emphasis
  on the photometric analysis of the observations.

Title: Reflections on Macrophysics and the Sun (Special Historical
    Review)
Authors: Parker, E. N.
Bibcode: 1997SoPh..176..219P
Altcode:
  No abstract at ADS

Title: New Constraints on Simultaneous Optical Emission From Gamma-Ray
    Bursts Measured by the Livermore Optical Transient Imaging System
    Experiment
Authors: Park, H. S.; Williams, G. G.; Ables, E.; Band, D. L.;
   Barthelmy, S. D.; Bionta, R.; Butterworth, P. S.; Cline, T. L.;
   Ferguson, D. H.; Fishman, G. J.; Gehrels, N.; Hartmann, D.; Hurley,
   K.; Kouveliotou, C.; Meegan, C. A.; Ott, L.; Parker, E.; Wurtz, R.
Bibcode: 1997ApJ...490L..21P
Altcode:
  LOTIS is a gamma-ray burst optical counterpart search experiment
  located near Lawrence Livermore National Laboratory in California. Since
  operations began in 1996 October, LOTIS has responded to five triggers
  as of 1997 July 30, which occurred during good weather conditions. <P
  />GRB 970223 (BATSE trigger 6100) was an exceptionally strong burst,
  lasting ~30 s with a peak at ~8 s. LOTIS began imaging the error box
  ~11 s after the burst began and achieved simultaneous optical coverage
  of 100% of the region enclosed by the BATSE 3 σ error circle and the
  interplanetary network annulus. No optical transients were observed
  brighter than the m<SUB>V</SUB>~11 completeness limit of the resulting
  images, providing a new upper limit on the ratio of simultaneous
  optical to gamma-ray fluence of R<SUB>L</SUB>&lt;1.1×10<SUP>-4</SUP>
  and on the ratio of simultaneous optical (at 700 nm) to gamma-ray (at
  100 keV) flux density of R<SUB>F</SUB>&lt;305 for a B-type spectrum
  and R<SUB>F</SUB>&lt;475 for an M-type spectrum.

Title: New Constraints on Simultaneous Optical Emission From GRBs
    Measured by the LOTIS Experiment
Authors: Park, H. S.; Williams, G. G.; Ables, E.; Band, D. L.;
   Barthelmy, S. D.; Bionta, R.; Butterworth, P. S.; Cline, T. L.;
   Ferguson, D. H.; Fishman, G. J.; Gehrels, N.; Hartmann, D.; Hurley,
   K.; Kouveliotou, C.; Meegan, C. A.; Ott, L.; Parker, E.; Wurtz, R.
Bibcode: 1997astro.ph..8130P
Altcode:
  LOTIS is a gamma-ray burst optical counterpart search experiment located
  near Lawrence Livermore National Laboratory in California. Since
  operations began in October 1996, LOTIS has responded to five
  triggers as of July 30, 1997, which occurred during good weather
  conditions. GRB970223 (BATSE Trigger #6100) was an exceptionally
  strong burst lasting $\sim30$ s with a peak at $\sim8$ s. LOTIS began
  imaging the error box $\sim 11$ s after the burst began, and achieved
  simultaneous optical coverage of 100% of the region enclosed by the
  BATSE $3\sigma$ error circle and the IPN annulus. No optical transients
  were observed brighter than the m$_V \sim 11$ completeness limit of
  the resulting images providing a new upper limit on the simultaneous
  optical to gamma-ray fluence ratio of $R_L &lt; 1.1 \times 10^{-4}$
  and on the simultaneous optical (at 700 nm) to gamma-ray (at 100 keV)
  flux density ratio of $R_F &lt; 305$ for a B type spectrum and $R_F &lt;
  475$ for an M type spectrum.

Title: Spontaneous current sheets and stellar x-ray emission
Authors: Parker, E. N.
Bibcode: 1997PPCF...39A...9P
Altcode:
  The x-ray emission from a star like the sun comes from plasma
  at 10<SUP>6</SUP>-10<SUP>7</SUP> K and 10<SUP>10</SUP> ions
  cm<SUP>-3</SUP>- trapped in the 100 Gauss bipolar magnetic fields
  of active regions. The x-ray intensity reaches 10<SUP>7</SUP> ergs
  cm<SUP>-2</SUP>s<SUP>-1</SUP>, which is a measure of the heat input
  required to maintain the temperature of the emitting gas. The basic
  energy input is photospheric convection, which swirls and intermixes the
  photospheric footpoints of the bipolar magnetic fields, thereby creating
  an interlaced topology of the field lines in the bipolar field above the
  photosphere. The basic theorem of magnetostatics asserts that almost
  all field topologies develop internal tangential discontinuities as
  the field relaxes to equilibrium. The discontinuities are a necessary
  and sufficient condition for the Maxwell stresses to achieve static
  balance. It appears that rapid reconnection across these internal
  current sheets provides the principal heat source for the x-ray corona.

Title: Reply
Authors: Parker, E. N.
Bibcode: 1997JGR...102.9657P
Altcode:
  No abstract at ADS

Title: Spontaneous current sheets and stellar x-ray emission
Authors: Parker, E. N.
Bibcode: 1997PPCF...39....9P
Altcode:
  No abstract at ADS

Title: Adventures With the Geomagnetic Field
Authors: Parker, E. N.
Bibcode: 1997dima.conf..143P
Altcode:
  No abstract at ADS

Title: Galactic Dynamos and Other Questions on the Origins of
    Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1997cdc..conf..309P
Altcode:
  No abstract at ADS

Title: Mass Ejection and a Brief History of the Solar Wind Concept
Authors: Parker, E. N.
Bibcode: 1997cwh..conf....3P
Altcode: 2006mslp.conf....3P
  No abstract at ADS

Title: S. Chandrasekhar and Magnetohydrodynamics
Authors: Parker, E. N.
Bibcode: 1996JApA...17..147P
Altcode:
  No abstract at ADS

Title: The X-ray Coronae of Solitary Late-Type Stars
Authors: Parker, E. N.
Bibcode: 1996SoPh..169..327P
Altcode:
  Recent observations of the motion of the footpoints of the bipolar
  magnetic fields of active X-ray regions of the Sun establish that the
  footpoints are intermixed on the same characteristic time and scale as
  the granule motions. It follows that the bipolar magnetic fields have
  an internally interlaced topology creating magnetic free energy. It
  follows from the basic theorem of magnetostatics that the topology
  creates internal surfaces of tangential discontinuity which effectively
  dissipate the magnetic free energy into heat. This process appears
  to be the cause of the X-ray coronae of solitary late Main-Sequence
  stars like the Sun.

Title: Comment on ``Current Paths in the Corona and Energy Release
    in Solar Flares''
Authors: Parker, E. N.
Bibcode: 1996ApJ...471..489P
Altcode:
  The dynamical behavior of an electrically conducting fluid containing
  a magnetic field B is described by Newton's and Maxwell's equations
  directly in terms of the momentum density, Reynolds stress, and Maxwell
  stress, all expressed simply in terms of B and v. The mathematical
  solution to the equations with the appropriate initial conditions (t =
  0) and boundary conditions on B and v provides a complete and unique
  description of B and v for t &gt; 0 so that further modifications
  are not possible. On the other hand, the electric current paradigm
  urged by Melrose provides dynamical equations that are mathematically
  intractable. The declaration of an electric current analog to replace a
  mathematical solution of the dynamical equations yields results that are
  at variance with the solutions of Newton's and Maxwell's equations. We
  suggest that a proper solution of the equations in terms of B and v
  is the preferable modus operandi in large-scale astronomical scenarios.

Title: Inferring Mean Electric Currents in Unresolved Fibril
    Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1996ApJ...471..485P
Altcode:
  It is shown that the curl of the transverse magnetogram of magnetic
  fields composed of unresolved separate fibrils bears no direct relation
  to the mean longitudinal electric current density. The mean current
  density is essentially zero, regardless of the spatial variation and
  torsion of the mean field.

Title: The alternative paradigm for magnetospheric physics
Authors: Parker, E. N.
Bibcode: 1996JGR...10110587P
Altcode:
  This paper emphasizes that the macrodynamics of the terrestrial
  magnetosphere is more effectively treated in terms of the primary
  variables B and v (the B, v paradigm). The common practice of relating
  the dynamics to E and j (the E, j paradigm) provides direct answers
  in a variety of symmetric cases, but breaks down in even so simple
  a static problem as a flux bundle displaced (perhaps by reconnection
  with the magnetic field in the solar wind) from its normal equilibrium
  position in a static dipole field. The essential point is that a
  direct derivation from the equations of Maxwell and Newton leads
  to field equations written in terms of the continuum fields B and
  v. The equations can be recast in terms of E and j, of course, but
  they are then unwieldy, being integrodifferential equations. Hence
  the E, j paradigm, when correctly applied, is seriously limited
  in its effectiveness in dynamical problems. Circumventing the
  limitations with the common declaration that E is the prime mover,
  actively penetrating from the solar wind into the magnetosphere,
  provides dynamics that is unfortunately at variance with the results
  that follow directly from Maxwell and Newton. The paper outlines the
  standard derivation of the basic field equations and then goes on to
  treat a variety of circumstances to illustrate the effectiveness of
  the deductive B, v paradigm in the continuum dynamics of the magnetic
  field and plasma. There is no attempt to develop a comprehensive model
  of magnetospheric activity. However we suggest that the ultimate task
  is more effectively attacked with the B, v paradigm.

Title: The Sun as the Ultimate Challenge to Astrophysics: The Vital
    Phase of Solar Physics
Authors: Parker, E. N.
Bibcode: 1996mpsa.conf..399P
Altcode: 1996IAUCo.153..399P
  No abstract at ADS

Title: Solar variability and teffestrial climate.
Authors: Parker, E. N.
Bibcode: 1996sube.conf..117P
Altcode:
  No abstract at ADS

Title: Questions and conjectures on the origin of stellar and galactic
    magnetic fields.
Authors: Parker, E.
Bibcode: 1996ASIC..481....1P
Altcode:
  The magnetic fields of the Sun and the Galaxy, as prototypes of the
  fields of other stars and galaxies, appear to originate in some form
  or variant of the well known αω-dynamo. However, the αω-dynamo
  can function only in the presence of irreversible diffusion and
  dissipation of the small-scale internal magnetic fields, requiring
  effective diffusion coefficients of the order of 10<SUP>12</SUP>
  and 10<SUP>25</SUP> cm<SUP>2</SUP>/sec for the Sun and Galaxy,
  respectively. It is hypothesized that the magnetic field of the Sun
  is in an intensely fibril state throughout the convective zone, with
  rapid reconnection wherever nonparallel fibrils are pressed together
  by the fluid motions. The result of this scenario would seem to be a
  sufficiently rapid irreversible interdiffusion of fields for successful
  operation of the solar dynamo. For the Galaxy it is hypothesized that
  rapid reconnection between the extended magnetic lobes or Ω-loops
  that form the halo accomplished the irreversibility necessary for the
  operation of the galactic dynamo.

Title: Some implications of solar and stellar activity.
Authors: Parker, E.
Bibcode: 1996ASIC..481..337P
Altcode:
  The astonishing variability and suprathermal activity of the Sun and
  similar stars is presened as a problem in physics, about which there is
  currently more conjecture than hard fact. Attention is directed to the
  coronal hole, the active X-ray corona, and to the overall variation in
  solar brightness. The variation of solar brightness has profound effect
  on terrestrial climate. The observational difficulties are listed.

Title: Theoretical Properties of Omega -Loops in the Convective Zone
    of the Sun. V. Coriolis Force and the Centrifugal Potential Barrier
Authors: Parker, E. N.
Bibcode: 1995ApJ...454..927P
Altcode:
  The effect of Coriolis force and centrifugal force on a rising sheet
  of fluid in an otherwise rigidly rotating fluid body (representing
  an idealized solar convective zone) is treated, showing the minor
  effect on the Kelvin-Helmholtz instability of the rising sheet. The
  principal effect is the reduction of the small centrifugal force on an
  element of fluid responding to the Coriolis force. The result is that
  a substantially steeper ambient superadiabatic temperature gradient
  is required if the rising fluid is not to be cut off by the ambient
  hydrostatic pressure. This result suggests the theoretical possibility
  that there may be substantial activity of buoyant flux bundles in the
  lower convective zone that is prevented from showing itself at the
  visible surface of the Sun.

Title: Subrahmanyan Chandrasekhar, 19 October 1910 - 21 August 1995.
Authors: Parker, E. N.
Bibcode: 1995PhT....48k.106P
Altcode:
  No abstract at ADS

Title: Theoretical Properties of the Omega -Loops in the Convection
    Zone of the Sun. IV. Stability of Updrafts
Authors: Parker, E. N.
Bibcode: 1995ApJ...448..942P
Altcode:
  This paper treats the Kelvin-Helmholtz instability of a two-dimensional
  stream of fluid simulating the convective updraft described in the
  two previous papers. It appears that the instability is strong enough
  by itself to dismember at least the upper end of a columnar updraft
  extending up from the bottom of the convective zone. On the other
  hand, the tension in the vertical legs of accumulated Ω-loops may
  suppress the instability in the upper portion of the updraft if the
  magnetic field is in an intense fibril state. The eddy viscosity of the
  ambient convection may be as large as 10<SUP>13</SUP> cm<SUP>2</SUP>
  s<SUP>-1</SUP>, in which case it too may stabilize the updraft
  to some degree. In conclusion, it appears that the updraft may be
  sufficiently stable to be recognizable as a coherent dynamical form,
  thereby fulfilling the observational requirement that the Ω-loops
  emerge through a localized (and only slowly shifting) site at the
  visible surface. The coherence over the height of the convective zone
  is the basis for the conjecture that the updraft, created by successive
  emerging Ω-loops, is the principal cause of the enhancement of solar
  irradiance during periods of high solar activity.

Title: Physics of the Sun: The Ultimate Challenge to Astrophysics
Authors: Parker, E. N.
Bibcode: 1995SPD....26.1212P
Altcode: 1995BAAS...27..985P
  No abstract at ADS

Title: Theoretical Properties of Omega -Loops in the Convective Zone
    of the Sun. III. Extended Updrafts
Authors: Parker, E. N.
Bibcode: 1995ApJ...442..405P
Altcode:
  It was pointed out in an earlier paper that the continuing emergence
  of Omega-loops at localized sites on the surface of the Sun indicates
  a continuing updraft at those sites. The updraft evidently extends
  all the way from the base of the convective zone to somewhat near
  (approximately 10<SUP>9</SUP>cm) the surface. We pointed out that
  such updrafts enhance the convective heat transport to the surface,
  accounting for a major part of the increased solar brightness or
  irradiance during times of solar activity. The problem is to work out,
  as much as possible, the dynamical nature of the extended updrafts,
  initiated as the wakes of successive rising Omega-loops and driven
  thereafter by the convective forces. The question is, does the updraft
  take on a long-lived columnar form of its own, or does it never devlop
  beyond a sequence of rising wakes, resembling beads on a string? The
  dynamics of a columnar updraft is complicated by both the large
  Reynolds number and the strong stratication of the atmosphere, and by
  a total lack of direct observational information. Extended slender
  updrafts are not a spontaneous occurrence in numerical simulations
  of thermal convection in a stratified atmosphere, although slender
  concentrated downdrafts commonly occur. This paper examines several
  aspects of a columnar updrft in a convective atmosphere under various
  idealized circumstances to investigate to what extent that state can
  be maintained against the diminishing vorticity and expansion in the
  updraft. It appears that the successive passage of Omega-loops from
  the bottom to the top of the convective zone is an essential feature
  of the continuing existence of the updraft.

Title: Theoretical Properties of Omega -Loops in the Convective Zone
    of the Sun. II. The Origin of Enhanced Solar Irradiance
Authors: Parker, E. N.
Bibcode: 1995ApJ...440..415P
Altcode:
  The brightness of the Sun is observed to vary by 0.2% with the 11 yr
  activity cycle. We suggest that the brightness increase with magnetic
  activity is a direct result of the enhanced heat transport provided
  by the vertical wakes of the successive Omega-loops of magnetic
  field that produce the activity. The dynamics of a vertical wake in
  a stratified atmosphere is relatively complicated, but the observed
  rapid succession of emergence of Omega-loops at a localized site in
  the middle of a bipolar active region can be understood only if an
  established concentrated updraft extends up from the bottom of the
  convective zones. It is these updrafts that we suggest are the major
  cause of the brightness enhancement. The next paper examines some of
  the dynamical characteristics of vertical wakes.

Title: GONG and The Solar Dynamo
Authors: Parker, E. N.
Bibcode: 1995ASPC...76....3P
Altcode: 1995gong.conf....3P
  No abstract at ADS

Title: The Magnetic Field of the Galaxy
Authors: Parker, E. N.
Bibcode: 1995fras.conf..115P
Altcode:
  No abstract at ADS

Title: Vital phase of space science
Authors: Parker, E. N.
Bibcode: 1994JGR....9919155P
Altcode:
  Space science began with the indirect phase where the activity in
  space was inferred from such terrestrial phenomena as geomagnetic
  storms, ionospheric variations, and fluctuations in the cosmic ray
  intensity. The direct phase was initiated with spaceflight placing
  instruments directly in space and permitting the direct observation of
  UV and X rays, as well as precision observations of solar luminosity
  variations. The evidence from these many direct studies, together
  with the historical record of terrestrial conditions, shows that
  the variations of the luminosity of the Sun affect the terrestrial
  atmosphere at all levels, with devastating changes in climate tracking
  the major changes in the activity level and luminosity of the Sun. The
  quantification and understanding of this vital connection should be
  the first priority of space science and geophysics, from oceans and
  atmosphere through the ionosphere, magnetosphere, and all the way to the
  convective zone of the Sun. It becomes the vital phase of space science,
  focused on the basic science of the changing habitability of Earth.

Title: Theoretical Properties of Omega -Loops in the Convective Zone
    of the Sun. I. Emerging Bipolar Magnetic Regions
Authors: Parker, E. N.
Bibcode: 1994ApJ...433..867P
Altcode:
  It is proposed that the observed 500 G intensity of the magnetic fields
  emerging through the surface of the Sun can be understood from the
  Bernoulli effect in the upwelling Omega-loops of magnetic field. It is
  also proposed that the inferred 10<SUP>5</SUP> G azimuthal flux bundles
  below the base of the convective zone can be understood as a consequence
  of the large-scale buoyancy associated with the upwelling fluid in and
  around the rising Omega-loop. The process fits in naturally with the
  Babcock-Leighton form of the solar alpha-omega-dynamo. The emerging
  Omega-loop implies the coherence of the upwelling all the way from the
  bottom of the convective zone, enhancing the convective heat transport
  to account for the observed variation of the solar irradiance by about
  two parts in 10<SUP>3</SUP>.

Title: Comments and Perspectives
Authors: Parker, E. N.
Bibcode: 1994ASPC...68..413P
Altcode: 1994sare.conf..413P
  No abstract at ADS

Title: Origins of the Solar Magnetic Field
Authors: Parker, E. N.
Bibcode: 1994smf..conf...94P
Altcode:
  No abstract at ADS

Title: Summary comments
Authors: Parker, E. N.
Bibcode: 1994seit.conf..527P
Altcode:
  No abstract at ADS

Title: Replacement Concepts for Turbulent Diffusion of Magnetic
    Fields in Stars and Galaxies
Authors: Parker, E. N.
Bibcode: 1994ASIC..422..123P
Altcode: 1994coma.conf..123P
  No abstract at ADS

Title: Theoretical Interpretation of Magnetic Activity
Authors: Parker, E. N.
Bibcode: 1994svsp.coll..264P
Altcode: 1994IAUCo.143P.264P
  No abstract at ADS

Title: Spontaneous current sheets in magnetic fields : with
    applications to stellar x-rays
Authors: Parker, Eugene Newman
Bibcode: 1994ISAA....1.....P
Altcode: 1994QB529.P36......
  Expanding upon the ideas first proposed in his seminal book Cosmical
  Magnetic Fields , Eugene N. Parker here offers the first in-depth
  treatment of the magnetohydrodynamic theory of spontaneous magnetic
  discontinuities. In detailing his theory of the spontaneous formation
  of tangential discontinuities (current sheets) in a magnetic field
  embedded in highly conducting plasma, Parker shows how it can be used
  to explain the activity of the external magnetic fields of planets,
  stars, interstellar gas clouds, and galaxies, as well as the magnetic
  fields in laboratory plasmas. Provocative and fascinating, Spontaneous
  Current Sheets in Magnetic Fields presents a bold new theory that will
  excite interest and discussion throughout the space physics community.

Title: Anomalous Resistivity and the Evolution of Magnetic Field
    Topology
Authors: Parker, E. N.
Bibcode: 1993ApJ...414..389P
Altcode:
  This paper explores the topological restructuring of a force-free
  magnetic field caused by the hypothetical sudden onset of a
  localized region of strong anomalous resistivity. It is shown that
  the topological complexity increases, with the primitive planar
  force-free field with straight field lines developing field lines that
  wrap half a turn around each other, evidently providing a surface of
  tangential discontinuity in the wraparound region. It is suggested
  that the topological restructuring contributes to the complexity of
  the geomagnetic substorm, the aurora, and perhaps some of the flare
  activity on the sun, or other star, and the Galactic halo.

Title: A Solar Dynamo Surface Wave at the Interface between Convection
    and Nonuniform Rotation
Authors: Parker, E. N.
Bibcode: 1993ApJ...408..707P
Altcode:
  A simple dynamo surface wave is presented to illustrate the basic
  principles of a dynamo operating in the thin layer of shear and
  suppressed eddy diffusion beneath the cyclonic convection in the
  convection zone of the sun. It is shown that the restriction of the
  shear delta(Omega)/delta(r) to a region below the convective zone
  provides the basic mode with a greatly reduced turbulent diffusion
  coefficient in the region of strong azimuthal field. The dynamo takes
  on the character of a surface wave tied to the lower surface z =
  0 of the convective zone. There is a substantial body of evidence
  suggesting a fibril state for the principal flux bundles beneath the
  surface of the sun, with fundamental implications for the solar dynamo.

Title: Resistive Dissipation and Magnetic Field Topology in the
    Stellar Corona
Authors: Parker, E. N.
Bibcode: 1993ApJ...407..342P
Altcode:
  Tangential discontinuities, or current sheets, in a magnetic
  field embedded in a fluid with vanishing resistivity are created
  by discontinuous fluid motion. Tangential discontinuities are also
  created when a magnetic field is allowed to relax to magnetostatic
  equilibrium after mixing by fluid motions (either continuous or
  discontinuous) into any but the simplest topologies. This paper
  shows by formal examples that the current sheets arising solely
  from discontinuous fluid motions do not contribute significantly to
  the dissipation of magnetic free energy when a small resistivity is
  introduced. Dissipation that is significant under coronal conditions
  occurs only by rapid reconnection, which arises when, and only when,
  the current sheets are required by the field topology. Hence it is
  topological dissipation that is primarily responsible for heating
  tenuous coronal gases in astronomical settings, whether the fluid
  displacements of the field are continuous or discontinuous.

Title: On the Generation of ``Strong'' Magnetic Fields
Authors: Vainshtein, S. I.; Parker, E. N.; Rosner, R.
Bibcode: 1993ApJ...404..773V
Altcode:
  We rediscuss the nature of magnetic field generation in astrophysical
  systems. We show that as a result of ineffective three-dimensional
  turbulent diffusion in the presence of strong azimuthal magnetic fields,
  the standard dynamo equations are not likely to provide a reasonable
  description of magnetic dynamos in systems such as late-type stars
  and galaxies. Instead, we propose a new set of dynamo equations,
  which take into account the modifications of turbulent diffusion by
  strong magnetic fields.

Title: Galactic cosmic rays and galactic halo X-ray emission
Authors: Parker, Eugene N.
Bibcode: 1993cac..book....3P
Altcode:
  No abstract at ADS

Title: Fast Dynamos, Cosmic Rays, and the Galactic Magnetic Field
Authors: Parker, E. N.
Bibcode: 1992ApJ...401..137P
Altcode:
  It is suggested here that the dynamo believed to be responsible
  for the magnetic field of the Galaxy is a fast dynamo due to the
  dynamical reconnection of the azimuthal field of the Galaxy as the
  field is deformed by the instability of the gaseous disk and the
  rapid inflation of magnetic lobes by the cosmic-ray gas to form the
  Galactic halo. The reconnection of adjacent lobes carries out both the
  alpha effect and field dissipation essential for the existence of the
  Galactic alpha-omega dynamo. The azimuthal field is generated primarily
  in the gaseous disk, while the alpha effect is carried out in the halo.

Title: Electron and Nuclear Counters
Authors: Parker, Eugene N.; Korff, Serge
Bibcode: 1992NYASA..65...30P
Altcode:
  No abstract at ADS

Title: Vortex Attraction and the Formation of Sunspots
Authors: Parker, E. N.
Bibcode: 1992ApJ...390..290P
Altcode:
  A downdraft vortex ring in a stratified atmosphere exhibits universal
  attraction for nearby vertical magnetic flux bundles. It is speculated
  that the magnetic fields emerging through the surface of the sun
  are individually encircled by one or more subsurface vortex rings,
  providing an important part of the observed clustering of magnetic
  fibrils to form pores and sunspots.

Title: The X Ray Corona, the Coronal hole, and the Heliosphere
Authors: Parker, E. N.
Bibcode: 1992JGR....97.4311P
Altcode:
  The X ray emission from the Sun arises primarily from the gas
  trapped in the bipolar magnetic fields of both small and large active
  regions. It appears that the trapped gas is heated by the intermittent
  dissipation of magnetic energy (nanoflares) at the current sheets
  that arise spontaneously in any magnetic field subject to continuous
  deformation. The solar wind issues from regions of weak field pushed
  open by the expanding corona. Most of the heat input is close to
  the Sun, in the first 1-2 R<SUB>S</SUB>, raising the gas slowly out
  through the gravitational field and gradually accelerating it through
  the speed of sound at a distance of perhaps 3-5 R<SUB>S</SUB>. The
  waves generated by photospheric convection dissipate only at distances
  of 5 R<SUB>S</SUB> and beyond, where their heat input and momentum
  accelerate the wind to the high velocities of 600-800 km/s sometimes
  observed. The only source for the principle heat input close to the
  Sun appears to be the network activity, as suggested by Martin, Porter,
  and Moore. Thus the mass loss and the formation of the heliosphere are
  primarily a consequence of the smallest-scale activity supplemented
  by occasional flares and coronal mass ejections. The X ray emission
  is largely a consequence of the smallest flares, the nanoflares,
  supplemented by occasional X ray bursts from large flares. It is
  presumed that the mass loss and associated circumstellar spheres and
  the X ray emission from most other stars arise in the same manner,
  although there is no possibility for detailed observation, of course.

Title: Heating coronal holes and accelerating the solar wind
Authors: Parker, E. N.
Bibcode: 1992sws..coll...79P
Altcode:
  The special energy requirements of a coronal hole combined with current
  knowledge of the limited dissipation of Alfven and fast mode MHD waves
  in the solar corona suggest a unique source of heat for the coronal
  hole. The near coronal hole requires approximately 3 - 4 x 10 exp 5
  ergs/sq cm s, which can come only from the fluid jets, fast particles,
  and short period MHD waves from the network activity. The high speed
  streams of solar wind from coronal holes show that there is substantial
  heating, of 1 - 2 x 10 exp 5 ergs/sq cm s, beyond the sonic point in
  the wind, which can come only from the dissipation by thermal conduction
  of long period (approximately equal or greater than 100 sec) MHD waves
  from subphotospheric convection. Although the Alfven wave flux from the
  photosphere is generally taken for granted in the literature, we point
  out that it is a crucial phenomenon that has yet to be established on
  either a theoretical or observational scientific basis.

Title: The Sunspot Phenomenon - a Commentary
Authors: Parker, E. N.
Bibcode: 1992ASIC..375..413P
Altcode: 1992sto..work..413P
  The current knowledge of the sunspot phenomenon is summarized, and
  some of the unanswered questions are identified. It is noted that
  the reason for the formation of sunspots remains the basic unanswered
  question. Attention is given to background considerations, formation
  of sunspots, the penumbra phenomenon, sunspot structure, and general
  theoretical problems.

Title: Dynamical Buoyancy of Hydrodynamic Eddies
Authors: Parker, E. N.
Bibcode: 1991ApJ...380..251P
Altcode:
  The dynamical pressure reduction within a vortex tube produces
  both a tension along the tube and a general buoyancy, analogous to
  magnetic flux tubes. The dynamical buoyancy causes convective cells
  to rise at speeds comparable to the rms fluid velocity within the
  cell. Consequently, the convective cells in a stratified atmosphere are
  more active than indicated by the standard anelastic approximation. The
  coherent convective cells at each level actively crowd upward into
  the convective cells above, elbowing weaker cells out of the way
  and flattening themselves and others against the upper surface of
  the convective region. These effects can be seen in the recent SOUP
  observations of the solar granulation. Deeper in the convective zone
  the inhomogeneity of the buoyancy may explain the random character of
  the convective motions that turns up in recent numerical simulations.

Title: The optical analogy for vector fields
Authors: Parker, E. N.
Bibcode: 1991PhFlB...3.2652P
Altcode:
  This paper develops the optical analogy for a general vector field. The
  optical analogy allows the examination of certain aspects of a vector
  field that are not otherwise readily accessible. In particular,
  in the cases of a stationary Eulerian flow v of an ideal fluid and a
  magnetostatic field B, the vectors v and B have surface loci in common
  with their curls. The intrinsic discontinuities around local maxima in
  absolute values of v and B take the form of vortex sheets and current
  sheets, respectively, the former playing a fundamental role in the
  development of hydrodyamic turbulence and the latter playing a major
  role in heating the X-ray coronas of stars and galaxies.

Title: Space plasma and its origin at the sun
Authors: Parker, E. N.
Bibcode: 1991PhFlB...3.2367P
Altcode:
  This paper provides a concise review of the large picture of space
  plasmas, concentrating on the heliosphere and the origin of the
  X-ray corona and coronal hole at the sun. It is tentatively suggested
  that the active X-ray corona is heated primarily by the dissipation
  of magnetic energy at the spontaneous tangential discontinuities
  (current sheets) in the confining bipolar magnetic fields of active
  regions. The discontinuities arise because of the continuous mapping
  of the footpoints of the field by the photospheric convection. The
  coronal holes appear to be heated by a combination of Alfven waves,
  providing the high-speed streams in the solar wind, and the microflaring
  in the small-scale network fields.

Title: The Magnetic Field of the Galaxy
Authors: Parker, E. N.
Bibcode: 1991ICRC....5...35P
Altcode: 1991ICRC...22e..35P
  No abstract at ADS

Title: The Phase Mixing of Alfven Waves, Coordinated Modes, and
    Coronal Heating
Authors: Parker, E. N.
Bibcode: 1991ApJ...376..355P
Altcode:
  Phase mixing has been a popular theoretical mechanism invoked to
  dissipate the photospheric plane shear Alfven waves hypothesized to
  penetrate up into the coronal hole and solar wind, thereby maintaining
  the expanding coronal gas at 1.5 million K and serving as the principal
  energy source for the solar wind. However, phase mixing requires
  an ignorable coordinate, which is not available in the presumably
  filamentary coronal hole. The filamentary density and temperature of
  the coronal hole couple the waves into a coordinated mode with a unique
  phase velocity omega/k, which provides the other popular theoretical
  mechanism, viz, resonant absorption where the local Alfven speed C is
  equal to omega/k. This provides coronal heating at radial distances
  O(10 solar radii), where it serves to accelerate the solar wind to
  high velocity. But it does not provide the principal heat input in
  the first 1-2 solar radii, required by Withbroe's (1988) analysis of
  the observed structure of the coronal hole.

Title: Heating Solar Coronal Holes
Authors: Parker, E. N.
Bibcode: 1991ApJ...372..719P
Altcode:
  It has been shown that the coronal hole, and the associated high-speed
  stream in the solar wind, are powered by a heat input of the order of
  500,000 ergs/sq cm s, with most of the heat injected in the first 1-2
  solar radii, and perhaps 100,000 ergs/sq cm s introduced at distances
  of several solar radii to provide the high speed of the issuing solar
  wind. The traditional view has been that this energy is obtained
  from Alfven waves generated in the subphotospheric convection, which
  dissipate as they propagate outward, converting the wave energy into
  heat. This paper reviews the generation of waves and the known wave
  dissipation mechanisms, to show that the necessary Alfven waves are
  not produced under the conditions presently understood to exist in
  the sun, nor would such waves dissipate significantly in the first
  1-2 solar radii if they existed. Wave dissipation occurs only over
  distances of the order of 5 solar radii or more.

Title: Convection, Spontaneous Discontinuities, and Stellar Winds
    and X-Ray Emission. (Karl Schwarzschild Lecture 1990)
Authors: Parker, E. N.
Bibcode: 1991RvMA....4....1P
Altcode:
  No abstract at ADS

Title: Micro/Nanoflare Coronal Heating (With 8 Figures)
Authors: Parker, E. N.
Bibcode: 1991mcch.conf..615P
Altcode:
  No abstract at ADS

Title: Intrinsic magnetic discontinuities and solar X-ray emission
Authors: Parker, E. N.
Bibcode: 1990GeoRL..17.2055P
Altcode:
  The fundamental theorem of magnetostatic equilibrium predicts that the
  bipolar magnetic fields of active regions on the Sun contain tangential
  discontinuities as an intrinsic part of their equilibrium. It appears
  that rapid reconnection at these many tangential discontinuities
  (nanoflares) is the primary source of heat that produces the X-ray
  emitting corona. The X-ray corona Is then a cloud of nanoflares.

Title: The solar probe mission
Authors: Feldman, W. C.; Anderson, J.; Bohlin, J. D.; Burlaga, L. F.;
   Farquhar, R.; Gloeckler, G.; Goldstein, B. E.; Harvey, J. W.; Holzer,
   T. E.; Jones, W. V.; Kellogg, P. J.; Krimigis, S. M.; Kundu, M. R.;
   Lazarus, A. J.; Mellott, M. M.; Parker, E. N.; Rosner, R.; Rottman,
   G. J.; Slavin, J. A.; Suess, S. T.; Tsurutani, B. T.; Woo, R. T.;
   Zwickl, R. D.
Bibcode: 1990AIPC..203..101F
Altcode: 1990pacr.rept..101F
  The Solar Probe will deliver a 133.5 kg science payload into a 4 Rs
  perihelion solar polar orbit (with the first perihelion passage in 2004)
  to explore in situ one of the last frontiers in the solar system-the
  solar corona. This mission is both affordable and technologically
  feasible. Using a payload of 12 (predominantly particles and
  fields) scientific experiments, it will be possible to answer many
  long-standing, fundamental problems concerning the structure and
  dynamics of the outer solar atmosphere, including the acceleration,
  storage, and transport of energetic particles near the Sun and in the
  inner (&lt;65 Rs) heliosphere.

Title: Solar and stellar coronae
Authors: Parker, E. N.
Bibcode: 1990AdSpR..10i..17P
Altcode: 1990AdSpR..10...17P
  A review of the observational facts of the X-ray corona of the sun
  suggests that the dissipation of waves plays at most a minor role in
  heating the corona. On the other hand, the random continuous shuffling
  and mixing of the footpoints of the bipolar magnetic fields, in which
  the X-ray corona resides, causes the spontaneous appearance of current
  sheets. Current sheets are highly dissipative, with a tendency to
  transient bursts of magnetic reconnection. Detailed observations show
  that the X-ray corona is made up of large numbers of small intense
  impulsive events of the same magnitude as expected from the bursts of
  reconnection. It appears, then, that it is the spontaneous current
  sheets that are the direct cause of the X-ray corona, driven by the
  continuous motions of the footpoints of the field in the photospheric
  convection.

Title: The Magnetic Field of the Sun - an Object Lesson
Authors: Parker, E. N.
Bibcode: 1990IAUS..140....1P
Altcode:
  The magnetic field of the sun is created by a magnetohydrodynamic
  dynamo under conditions bearing some qualitative similarities to the
  apparent generation of the Galactic field in the gaseous disk of the
  Galaxy. There is a similarity, too, in the extension of bipolar lobes
  of the solar field above the surface of the sun and the extension of
  bipolar lobes of the solar field above the surface of the sun and the
  extension of bipolar lobes of the Galactic field outward from both sides
  of the disk. The expected origin and activity of the galactic field
  can be studied by examining the behavior of the magnetic field of the
  sun. The origin of the solar magnetic field far below the surface can
  be investigated as can the theoretical origin of the Galactic field,
  where there is so little direct observation of the small scale motions
  and magnetic fields. The activity of the magnetic field of the sun,
  producing prominences, flares and X-ray corona, a solar wind, and
  coronal mass ejection, can all have counterparts in the activity of
  the Galactic field above the surface of the gaseous disk.

Title: Bowie medal to Eugene N. Parker; Citation and reply
Authors: Jokipii, J. R.; Parker, E. N.
Bibcode: 1990EOSTr..71..783J
Altcode:
  On May 30, 1990, at the Spring Meeting in Baltimore, Md., AGU
  honored Eugene N. Parker of the University of Chicago with its most
  prestigious award, the William Bowie Medal. The annual award is
  given for outstanding contributions to fundamental geophysics and for
  unselfish cooperation in research. The award citation and Parker's
  response are presented below.

Title: Spontaneous Discontinuities in Galactic Magnetic Fields and
    the Creation of Galactic X-Ray Halos
Authors: Parker, E. N.
Bibcode: 1990IAUS..140..169P
Altcode:
  The magnetic field in the gaseous disk of the Galaxy is dynamically
  unstable to undulations with wavelenghts of the order of 1 kpc. The
  elevated portions of the field are subject to rapid inflation
  (of about 5 km/sec) by the cosmic rays produced within the gaseous
  disk. The result is a magnetic halo of 1-3 x 10 to the -6th gauss,
  composed of close packed bipolar lobes of field extending outward from
  the surface of the disk to distances of several kpc. The inflation is
  presumably irregular, producing tangential discontinuities (current
  sheets) throughout the extended bipolar fields. A major portion of the
  magnetic energy is dissipated by rapid reconnection at these current
  sheets, heating the tenuous halo gas to temperatures of 10 to the 6th
  to 10 to the 7th K and producing the X-ray emission observed from the
  halos of many spiral galaxies.

Title: The basic magnetostatic theorem.
Authors: Parker, E. N.
Bibcode: 1990ppst.conf....3P
Altcode:
  The purpose of this paper is to familiarize the reader with a basic
  theorem of magnetohydrodynamics, that tangential discontinuities
  (current sheets) are an intrinsic part of the magnetostatic equilibrium
  of all but the simplest field topologies. A tangential discontinuities
  here refers to a surface (flux surface) across which the magnitude of
  the field is continuous but the direction is not. This theorem can be
  applied to the theory of heating the solar corona.

Title: The cause of the solar X-ray corona.
Authors: Parker, E. N.
Bibcode: 1990ppst.conf...63P
Altcode:
  This lecture takes a critical look at the cause of the active X-ray
  corona of the Sun to determine how this remarkable suprathermal
  phenomenon is produced. The traditional ideas run into serious
  quantitative difficulty when confronted with observation. The
  theoretical considerations suggest that the active X-ray corona is
  maintained largely by many small reconnection events in the tangential
  discontinuities that arise spontaneously in the bipolar magnetic
  fields. Alfvén waves are undoubtedly present in the bipolar fields,
  but their total contribution to the energy input to the active corona
  is, evidently, minor.

Title: Tangential discontinuities and the optical analogy for
    stationary fields. VII. Effects of resistivity
Authors: Parker, E. N.
Bibcode: 1990GApFD..55..161P
Altcode:
  The relatively large resistivity in the solar photosphere and
  chromosphere softens the ideal tangential discontinuities of
  magnetostatic equilibrium into continuous transitions in field direction
  over scales of 0.1-10 km. This softening is communicated upward at the
  Alfvén speed into the active solar corona. The degree of softening
  is a vital part of the theory of magnetic heat input to the active
  X-ray corona, because the very low resistivity of the coronal gas
  provides effective dissipation only if the current sheets are reduced
  to a thickness of 10-2km. A close examination of the problem shows
  that the Alfvén transit time up into the corona is large compared
  to the characteristic time of 1 sec in which the coronal tangential
  discontinutities are formed. It also shows that the principal effect of
  the resistivity is to create a thin surface layer of fluid on adjacent
  flux bundles, which causes a general drift of the flux but does not
  directly broaden the current sheets higher up in the field. In fact
  the motions of the surface layers do not extend upwards beyond the
  first winding pattern at each end of a coronal loop. It appears that
  the photospheric and chromospheric resistivity is without striking
  consequences for magnetic heating in the corona.

Title: Spontaneous tangential discontinuities and the optical analogy
    for static magnetic fields. VI. Topology of current sheets
Authors: Parker, E. N.
Bibcode: 1990GApFD..53...43P
Altcode:
  The electric surface current in a tangential discontinuity in a
  force-free magnetic field is conserved. The direction of the current
  is halfway between the direction of the continuous fields on either
  side of the surface of discontinuity. Hence the current sheets,
  i.e. the surface of tangential discontinuity, have a topology that is
  distinct from the lines of force of the field. The precise nature of
  the topology of the current sheet depends upon the form of the winding
  patterns in the field. Hence, invariant winding patterns and random
  winding patterns are treated separately. Current sheets may have edges,
  at the junction of two or more topological separatrices. The current
  lines may, in special cases, be closed on themselves. The lines of force
  that lie on either side of a current sheet somewhere pass off the sheet
  across a junction onto another sheet. In most cases the current sheets
  extending along a field make an irregular honeycomb. The honeycomb
  pattern varies along the field if the winding pattern of the field
  varies. The surface current density in a tangential discontinuity
  declines inversely, or faster, with distance from its region of
  origin. The edges of weaker tangential discontinuities (originating
  in more distant regions) are bounded by the stronger tangential
  discontinuities (of nearby origin). An examination of the force-free
  field equations in a small neighborhood of the line of intersection
  of two tangential discontinuities shows that the lines of force twist
  around to cross the line of intersection at right angles. If the angle
  between the tangential discontinuities exceeds /2, there is also the
  possibilitity that the lines twist around so as to come tangent to
  the line of intersection as they cross it.

Title: Tangential discontinuities and the optical analogy for
    stationary fields. v. formal integration of the force-free field
    equations
Authors: Parker, E. N.
Bibcode: 1990GApFD..52..183P
Altcode:
  This paper demonstrates the appearance of tangential discontinuities
  in deformed force-free fields by direct integration of the field
  equation x B = B. To keep the mathematics tractable the initial
  field is chosen to be a layer of linear force-free field Bx = +
  B0cosqz, By = - B0sinqz, Bz = 0, anchored at the distant cylindrical
  surface π = (x2 + y2)1/2 = R and deformed by application of a local
  pressure maximum of scale l centered on the origin x = y = 0. In the
  limit of large R/l the deformed field remains linear, with α = q[1 +
  O(l2/R2)]. The field equations can be integrated over π = R showing a
  discontinuity extending along the lines of force crossing the pessure
  maximum. On the other hand, examination of the continuous solutions to
  the field equations shows that specification of the normal component
  on the enclosing boundary π = R completely determines the connectivity
  throughout the region, in a form unlike the straight across connections
  of the initial field. The field can escape this restriction only by
  developing internal discontinuities. <BR /><BR />Casting the field
  equation in a form that the connectivity can be specified explicitly,
  reduces the field equation to the eikonal equation, describing the
  optical analogy, treated in papers II and III of this series. This
  demonstrates the ubiquitous nature of the tangential discontinuity in
  a force-free field subject to any local deformation.

Title: Tangential discontinuities and the optical analogy for
    stationary fields IV. High speed fluid sheets
Authors: Parker, E. N.
Bibcode: 1990GApFD..50..229P
Altcode:
  It was shown in the previous paper that a sufficiently strong pressure
  maximum applied to an equilibrium flux surface, by the fields on either
  side of the surface, produces a gap in the flux surface. The fields
  on either side make contact through the gap to produce a surface of
  tangential discontinuity (current sheet). It is shown in the present
  paper that there is a high speed sheet of fluid and field sliding over
  the surface of discontinuity when the applied pressure moves slowly
  across the flux surface. Conditions in the active X-ray corona of the
  sun suggest that such sheets are generally present, with velocities
  of the order of 102 km/sec, but with thicknesses too small to be
  observed. More substantial high speed sheets of fluid may occur in
  solar flares.

Title: Intermittent Behavior of Galactic Dynamo Activities
Authors: Ko, C. M.; Parker, E. N.
Bibcode: 1989ApJ...341..828K
Altcode:
  Recent observations by Beck and Golla of far-infrared and radio
  continuum emission from nearby spiral galaxies suggest that the
  galactic magnetic field strength is connected to the current star
  formation rate. The role of star formation on the generation of
  large-scale galactic magnetic field is studied in this paper. Using
  a simple galactic model, it is shown how the galactic dynamo depends
  strongly on the turbulent velocity of the interstellar medium. When
  the star formation efficiency is high, the ISM is churned which
  in turn amplifies the galactic magnetic field. Between active star
  formation epochs, the magnetic field is in dormant state and decays
  at a negligible rate. If density waves trigger star formation, then
  they also turn on the otherwise dormant dynamo.

Title: Solar and Stellar Magnetic Fields and Atmospheric Structures
    - Theory
Authors: Parker, E. N.
Bibcode: 1989SoPh..121..271P
Altcode: 1989IAUCo.104..271P
  This presentation reviews selected ideas on the origin of the magnetic
  field of the Sun, the dynamical behavior of the azimuthal field in the
  convective zone, the fibril state of the field at the photosphere,
  the formation of sunspots, prominences, the spontaneous formation
  of current sheets in the bipolar field above the surface of the Sun,
  coronal heating, and flares.

Title: Tangential discontinuities and the optical analogy for
    stationary fields III. Zones of exclusion
Authors: Parker, E. N.
Bibcode: 1989GApFD..46..105P
Altcode:
  This paper presents a number of formal examples of the bifurcation
  of individual flux surfaces by the pressure maxima imposed by
  the fields on either side. An approximate necessary and sufficient
  criterion for the convexity of the pressure maximum is provided, with
  application to fields with and without gaps in their flux surfaces. Gaps
  automatically produce tangential discontinuities in almost all cases,
  by permitting fields otherwise separated by finite distance to come in
  contact. Both Euclidean and non Euclidean flux surfaces are examined,
  showing that positive curvature fosters the formation of gaps while
  negative curvature opposes it. The special conditions for producing
  single or double gaps are pointed out. The general conditions for
  producing gaps are so mild as to indicate the special character of the
  familiar continuous solutions to the force-free equilibrium equations,
  in which the maxima and minima of the field pressure are so arranged
  as to provide flux surfaces without gaps.

Title: Spontaneous tangential discontinuities and the optical analogy
    for static magnetic fields. I. Force-free fields, potential fields,
    and discontinuities
Authors: Parker, E. N.
Bibcode: 1989GApFD..45..159P
Altcode:
  The lines of force of a magnetic field extending through an infinitely
  conducting fluid between footpoints on the planes z=0 and z=L can be
  wrapped and interwoven by bounded continuous motions of the footpoints
  into a random sequence of arbitrary topological patterns along the
  field. The sign of the topological helicity of the winding pattern
  of the field vanes at random along the field. On the other hand, in
  force-free equilibrium the relative helicity (=B. B/B2) is rigorously
  constant along each line of force. Indeed in the limit of an endless
  random sequence of independent winding patterns along the field,
  the helicity falls asymptotically to zero and the field becomes curl
  free. A field with constant helicity along each line of force is
  obliged to create internal tangential discontinuities (in which the
  sign of the curl and the helicity is arbitrary) if it is to follow
  the varying topological helicity imposed by the twists and turns of
  the succession of independent winding patterns.

Title: Tangential discontinuities and the optical analogy for
    stationary fields II. The optical analogy
Authors: Parker, E. N.
Bibcode: 1989GApFD..45..169P
Altcode:
  It is shown that any stationary three-dimensional velocity field
  or magnetic field is a potential field in the two dimensional
  subspace of the Bernoulli surfaces S(Q) or isobaric surfaces S(p),
  respectively. From this it is shown that the streamlines and the lines
  of force follow the optical ray paths in S(Q) and S(p) for indices of
  refraction v and B, respectively. This formal analogy shows how the
  lines are refracted by variations of the pressure applied by the fluid
  and field on either side. In particular, it is shown how continuous
  variations of the pressure produce discontinuities (bifurcations)
  in the field, forming tangential discontinuities.

Title: Nanoflares and the Solar X-Ray Corona
Authors: Parker, E. N.
Bibcode: 1988ApJ...330..474P
Altcode:
  Observations of the sun with high time and spatial resolution in UV and
  X-rays show that the emission from small isolated magnetic bipoles is
  intermittent and impulsive, while the steadier emission from larger
  bipoles appears as the sum of many individual impulses. We refer
  to the basic unit of impulsive energy release as a nanoflare. The
  observations suggest, then, that the active X-ray corona of the sun
  is to be understood as a swarm of nanoflares. This interpretation
  suggests that the X-ray corona is created by the dissipation at the
  many tangential discontinuities arising spontaneously in the bipolar
  fields of the active regions of the sun as a consequence of random
  continuous motion of the footpoints of the field in the photospheric
  convection. The quantitative characteristics of the process are inferred
  from the observed coronal heat input.

Title: Dynamical Oscillation and Propulsion of Magnetic Fields in
    the Convective Zone of a Star. V. Instability and Propulsion of
    Flux Bundles
Authors: Parker, E. N.
Bibcode: 1988ApJ...326..395P
Altcode:
  Simple analysis of the hydrodynamics initiated by the presence of a
  coherent flux bundle in the lower half of the convective zone of a star
  like the Sun indicates that bundles with diameters comparable to the
  local pressure scale height (∼5 x 10<SUP>9</SUP> cm) are subject to
  sidewise motions perhaps as fast as 10<SUP>3</SUP> cms<SUP>-1</SUP>. The
  motions arise as a consequence of the bundle being squeezed between
  the cool shadow above and the accumulating heat below, and because
  of convective propulsion. This suggests that the equatorward motion
  (10<SUP>2</SUP> cm s<SUP>-1</SUP>) of the azimuthal fields, inferred
  from observations of the Sun, may be as much a consequence of the
  hydrodynamics of flux bundles and meridional circulation as it is of
  the dynamo effects that create the flux.

Title: Dynamical oscillation and propulsion of magnetic fields in the
    convective zone of a star. VI - Small flux bundles, network fields,
    and ephemeral active regions
Authors: Parker, E. N.
Bibcode: 1988ApJ...326..407P
Altcode:
  Simple analysis of the hydrodynamics initiated by the presence of a
  coherent flux bundle in the lower half of the convective zone of a star
  like the Sun indicates that bundles with diameters comparable to the
  local pressure scale height (5 x 10 cm) are subject to sidewise motions
  perhaps as fast as 10 cm 51 The motions arise as a consequence of the
  bundle being squeezed between the cool shadow above and the accumulating
  heat below, and because of convective propulsion. This suggests
  that the equatorward motion (102 cm s1) of the azimuthal fields,
  inferred from observations of the Sun, may be as much a consequence
  of the hydrodynamics of flux bundles and meridional circulation as
  it is of the dynamo effects that create the flux. Subject headings:
  hydromagnetics - stars: interiors stars: magnetic

Title: Dynamical Oscillation and Propulsion of Magnetic Fields in
    the Convective Zone of a Star. IV. Eruption to the Surface
Authors: Parker, E. N.
Bibcode: 1988ApJ...325..880P
Altcode:
  It was shown in the previous paper that the heat accumulating beneath
  the azimuthal field in the convective zone of the sun initiates
  a Rayleight-Taylor instability, causing tongues of gas to intrude
  upward into the field. The present paper works out the conditions in an
  intruding tongue of gas, showing that it penetrates all the way through
  the field, emerging into the atmosphere above with a specific entropy
  significantly in excess of the ambient value. The entropy is large
  enough that the gas rises to the visible surface in 10 to the 6th s or
  less, where it produces a bipolar magnetic region. Once the eruption to
  the surface has carried away the accumulated hot gas below the field,
  there remains only the general downdraft which retracts the magnetic
  flux from the surface in a characteristic time of 10 to the 7th s.

Title: The origins of the stellar corona.
Authors: Parker, E. N.
Bibcode: 1988sscd.conf....2P
Altcode:
  This paper is a critical review of present observational facts and
  theoretical developments relating to the cause of the active X-ray
  corona and to the coronal holes of the sun and other late type stars.

Title: Magnetic Monopole Plasma Oscillations and the Survival of
    Galactic Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1987ApJ...321..349P
Altcode:
  This paper explores the general nature of magnetic-monopole plasma
  oscillations as a theoretical possibility for the observed Galactic
  magnetic field in the presence of a high abundance of magnetic
  monopoles. The modification of the hydromagnetic induction equation
  by the monopole oscillations produces the half-velocity effect,
  in which the magnetic field is transported bodily with a velocity
  midway between the motion of the conducting fluid and the monopole
  plasma. Observational studies of the magnetic field in the Galaxy, and
  in other galaxies, exclude the half-velocity effect, indicating that the
  magnetic fields is not associated with monopole oscillations. In any
  case the phase mixing would destroy the oscillations in less than 100
  Myr. The conclusion is that magnetic monopole oscillations do not play
  a significant role in the galactic magnetic fields. Hence the existence
  of galactic magnetic fields places a low limit on the monopole flux,
  so that their detection - if they exist at all - requires a collecting
  area at least as large as a football field.

Title: The Dynamical Oscillation and Propulsion of Magnetic Fields
    in the Convective Zone of a Star. II. Thermal Shadows
Authors: Parker, E. N.
Bibcode: 1987ApJ...321..984P
Altcode:
  The dynamics of thermal shadows which develop in the convective zone
  of a star around an insulating obstacle such as a horizontal band in
  intense magnetic field are studied. The depth of the shadow on the
  cool side of the obstacle is found to depend largely on the width of
  the obstacle multiplied by the temperature gradient. Thermal shadows
  pressing fields up to 10,000 G downward against the bottom of the
  convective zone are produced by the broad bands of the azimuthal field
  in the sun's convective zone. In the third part, the time-dependent
  accumulation of heat beneath a thermal barrier simulating such a band
  in the lower convective zone of the sun is considered. The resulting
  Rayleigh-Taylor instability is shown to cause tongues of heated gas
  to penetrate upward through the field, providing the emerging magnetic
  fields that give rise to the activity of the sun.

Title: The Dynamical Oscillation and Propulsion of Magnetic Fields
    in the Convective Zone of a Star. III. Accumulation of Heat and the
    Onset of the Reyleigh-Taylor Instability
Authors: Parker, E. N.
Bibcode: 1987ApJ...321.1009P
Altcode:
  This paper studies the time-dependent accumulation of heat beneath a
  thermal barrier simulating a broad band of intense azimuthal field in
  the lower convective zone of the Sun, or other star. The accumulating
  heat causes the gas density beneath the field to decline (Δρ/ρ =
  -ΔT/T) to the point that the gas is less dense than the gas within the
  magnetic field (where Δρ/ρ = -β<SUP>2</SUP>/8πp). The resulting
  Rayleigh-Taylor instability causes tongues of heated gas to penetrate
  upward through the field. We suggest that the tongues of hot gas take
  on the nature of thermal plumes, extending all the way to the surface,
  where they provide the emerging magnetic fields that give rise to the
  activity of the Sun. The whole process, beginning with the accumulation
  of heat, followed by the onset of the Rayleigh-Taylor instability,
  and the extension of tongues of hot gas into thermal plumes to the
  surface, is estimated to take a week or two, in agreement with the
  observed weekly emergence of thermal plumes and magnetic flux in
  activity complexes at the surface.

Title: Stimulated dissipation of magnetic discontinuities and the
    origin of solar flares.
Authors: Parker, E. N.
Bibcode: 1987SoPh..111..297P
Altcode:
  It is proposed that the principal cause of the confined solar flare is
  the dissipation of magnetic energy at the many small-scale pre-existing
  tangential dscontinuities in the local bipolar magnetic field. The
  discontinuities are a consequence of the continuous shuffling and
  intermixing of the footpoints of the bipolar field by the turbulent
  photospheric granules. The X-ray corona within the bipolar field
  is presumed to be a consequence of the continuing dissipation by
  reconnection at these discontinuities. A flare results when static
  deformation and/or internal agitation of the field stimulates the onset
  of rapid reconnection at the many small internal discontinuities. The
  discontinuities are partially exhausted by the flare, so that the
  post-flare X-ray emission of that particular loop is substantially below
  the pre-flare level for a period of some hours while the discontinuities
  are being rejuvenated.

Title: Small-scale energy storage and release as the cause of the
    stellar X-ray corona.
Authors: Parker, E. N.
Bibcode: 1987NASCP2483...89P
Altcode: 1987tphr.conf...89P
  It has yet to be established why ordinary stars possess X-ray
  coronas. Detailed observations of the Sun make it doubtful that the
  X-ray corona is produced by the dissipation of Alfven waves. The
  uniform X-ray brightness over all scales from 10,000 to 100,000 km
  simply does not look like a resonance phenomenon. It is demonstrated
  that the arbitrary winding patterns introduced into the bipolar magnetic
  fields of X-ray corona produce discontinuities within the field. It is
  suggested that the random motions of the footprints of the field cause
  the accumulation of internal strains in the field, which dissipate
  through neutral reconnection across the associated discontinuities to
  provide the primary heat source for the X-ray corona. It is emphasized,
  however, that the essential high resolution observations of the Sun
  have yet to be carried out, and until the theory is firmly established
  for the Sun, it cannot be known how to interpret the X-ray emission
  of the Sun or of the other stars.

Title: Why do stars emit x rays?
Authors: Parker, Eugene N.
Bibcode: 1987PhT....40g..36P
Altcode:
  Because X-ray emission is the principal means of energy loss from
  most stellar coronas, X-ray luminosity may be taken as a measure of
  the energy input needed to produce the corona. If, moreover, it were
  known why the sun is made to generate patches of bright X-ray corona,
  the X-ray emission could be used as a diagnostic tool for probing
  the properties of other stars. Attention is presently given to stars
  with surface temperatures below about 7000 K, such as the sun, to
  elucidate such phenomena as wrapping and interweaving of the magnetic
  lines of force in a bipolar magnetic region, the twisting of a single
  flux bundle in an otherwise uniform field, and future prospects being
  developed by NASA for more intensive study of solar X-ray processes.

Title: Magnetic Reorientation and the Spontaneous Formation of
    Tangential Discontinuities in Deformed Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1987ApJ...318..876P
Altcode:
  This paper provides an explicit illustration of the formation of
  tangential discontinuities (current sheets) in a force-free magnetic
  field whose footpoints have been subjected to bounded continuous
  displacement and shuffling, so that the lines of force are wound about
  each other in complex but continuous patterns. The discontinuities
  appear spontaneously because of the reorientation of the field under
  the enhanced pressure where two regions of different field topology
  are pressed together by the general winding and wrapping.

Title: The energy source of the interplanetary medium and the
    heliosphere.
Authors: Parker, Eugene N.
Bibcode: 1987NASCP2464...75P
Altcode: 1987ess..nasa...75P
  The activity of the interplanetary medium arises from occasional
  transient outbursts of the active corona and, for the most part, from
  the interaction of fast and slow streams in the solar wind. The basic
  driver is the heat input to the corona, both transient and steady. The
  fast streams issue from coronal holes where the heat input may be Alfven
  waves with root mean squared (rms) fluid velocities of nearly 100
  km/sec or may be wholly or in part the waves refracted into the hole
  from neighboring active regions. If the latter, then the character of
  the wind from the coronal hole depends upon the proximity and vigor of
  active regions, with significant differences between the polar and low
  altitude solar wind. In any case, there is no observational support for
  any of these ideas, so that the primary cause of the wind from the Sun,
  as well as any other similar star is not without mystery. It is to be
  hoped that ground-based observations together with the input from the
  Solar Optical Telescope and the International Solar Polar Mission may
  in time succeed in clearing up some of the basic questions.

Title: The Dynamo Dilemma
Authors: Parker, E. N.
Bibcode: 1987SoPh..110...11P
Altcode:
  The recent determination that the angular velocity Ω of the Sun
  declines downward through the convective zone raises serious questions
  about the nature of the solar dynamo. The principal qualitative features
  of the Sun are the azimuthal fields that migrate toward the equator
  in association with an oscillating poloidal field which reverses at
  about the time of maximum appearance of bipolar magnetic regions. If
  Ω decreases downward, or is negligible, the horizontal gradient in Ω
  produces a dynamo with some of these essential characteristics. There
  is reason to think that the dynamo is confined to the lower half of
  the convective zone where α has the opposite sign from the usual (α
  &gt; 0 in the northern hemisphere) producing equatorward migration
  but reversing the sign of the associated poloidal field. Meridional
  circulation may play an essential role in shaping the dynamo. At the
  present time it is essential to measure Ω accurately and determine
  the nature of the meridional circulation.

Title: The dynamical origin of active magnetic regions at the surface
    of theSun and other stars.
Authors: Parker, E. N.
Bibcode: 1987PBeiO...9....2P
Altcode:
  No abstract at ADS

Title: Magnetic Activity Complexes, Thermal Relaxation Oscillations,
    and the Dynamics of the Azimuthal Magnetic Field of a Star
Authors: Parker, E. N.
Bibcode: 1987ASSL..137..289P
Altcode: 1987isav.symp..289P
  The large amount of magnetic flux cycling through an activity complex
  in a period of six months suggests that the azimuthal magnetic field in
  the convective zone of the Sun is not less than 3×10<SUP>3</SUP>gauss
  and probably is considerable more. A field of 3 kilogauss or more
  has the effect of blocking the convective heat transport, producing a
  cool shadow above the azimuthal field and causing heat to accumulate
  below. The incremental weight of the cool shadow is sufficient to
  overpower the magnetic buoyancy, pressing the field against the bottom
  of the convective zone. The accumulation of heat underneath produces a
  thermal relaxation oscillation that erupts to the surface at intervals
  of the order of a week, supplying the intermittent emergence of magnetic
  flux observed in the activity complex.

Title: The causes of the corona of a star.
Authors: Parker, E. N.
Bibcode: 1987PBeiO...9....7P
Altcode:
  No abstract at ADS

Title: The Dynamical Oscillation and Propulsion of Magnetic Fields
    in the Convective Zone of a Star. I. General Considerations
Authors: Parker, E. N.
Bibcode: 1987ApJ...312..868P
Altcode:
  Observations of the sun show that the magnetic flux of the large
  activity complexes emerges in localized sites in brief bursts at
  intervals of many days or a few weeks. The quantity of flux arriving
  at the surface suggests that the mean aximuthal field of the sun in
  the lower convective zone is not less than 3000 G and may perhaps be
  considerably more. Such a field inhibits the convective transport of
  heat. Hence there is a cool shadow on the upper side of the field,
  and that cool shadow presses downward so hard as to suppress the
  magnetic buoyancy, forcing the field to remain in the lower convective
  zone. The accumulation of heat below the field forces intruding fingers
  of gas up through the field, forming thermal plumes extending up to
  the visible surface. It is suggested that the process is intermittent,
  providing a thermal relaxation oscillation with a period of the order
  of one week. The activity complexes observed at the surface are the
  consequence of these eruptions of fluid and entrained field from the
  lower convective zone.

Title: Magnetic Nonequilibrium and Current Sheet Formation
Authors: Vainshtein, S. I.; Parker, E. N.
Bibcode: 1987sman.work..201V
Altcode:
  This paper investigates the equilibrium of a cluster of long
  straight twisted magnetic flux tubes extending in the z-direction
  in a highly conducting fluid, subject to the boundary condition that
  the transverse component of the field (produced by the twisting) goes
  continuously to zero at the outer boundary of the flux tubes. It is
  shown that equilibrium requires that the length of the periphery of
  the tube remains invariant during any deformation of the tube. From
  this principle it is shown that there is equilibrium only for axial
  symmetry, i.e. only for a single twisted flux tube. These examples
  provide another perspective on the general absence of equilibrium,
  and consequent rapid dissipation, of any magnetic field subject to
  small-scale internal strains, such as the field extending outward from
  the convective zones of stars.

Title: Heating of the stellar corona.
Authors: Parker, E. N.
Bibcode: 1986NASCP2442....9P
Altcode: 1986copp.nasa....9P
  The present state of development of the theory of coronal heating is
  summarized. Coronal heating is the general cause of stellar X-ray
  emission, and it is also the cause of stellar mass loss in most
  stars. Hence a quantitive theory of coronal heating is an essential
  part of X-ray astronomy, and the development of a correct theory of
  coronal heating should be a primary concern of X-ray astronomers. The
  magnetohydrodynamical effects involved in coronal heating are not
  without interest in their own right, representing phenomena largely
  unknown in the terrestrial laboratory. Until these effects can be
  evaluated and assembled into a comprehensive theory of coronal heating
  for at least one star, the interpretation of the X-ray emissions of
  all stars is a phenomenological study at best, based on arbitrary
  organization and display of X-ray luminosity against bolometric
  luminosity, rotation rate, etc. The sun provides the one opportunity
  to pursue the exotic physical effects that combine to heat a stellar
  corona.

Title: Stellar challenge
Authors: Parker, Eugene N.
Bibcode: 1986Natur.323..210P
Altcode:
  No abstract at ADS

Title: Book-Review - Physics of the Sun - V.I - the Solar Interior
    - V.II - the Solar Atmosphere - V.III - Astrophysics and Solar /
    Terrestrial Relations
Authors: Sturrock, P. A.; Holzer, T. E.; Mihalas, D. M.; Ulrich,
   R. K.; Parker, E. N.
Bibcode: 1986Natur.323..210S
Altcode:
  No abstract at ADS

Title: Magnetic Nonequilibrium and Current Sheet Formation
Authors: Vainshtein, S. I.; Parker, E. N.
Bibcode: 1986ApJ...304..821V
Altcode:
  This paper investigates the equilibrium of a cluster of long,
  straight, twisted magnetic flux tubes extending in the z-direction
  in a highly conducting fluid, subject to the boundary condition
  that the cluster is surrounded by a uniform pressure P. It is shown
  that there is equilibrium only for axial symmetry, i.e., only for a
  single twisted flux tube. Any more complicated cluster of twisted
  tubes is subject to nonequilibrium reconnection of the transverse
  component of the field. The example provides another perspective on
  the general absence of equilibrium, and consequent rapid dissipation,
  of any magnetic field subject to random small-scale internal strains,
  such as the fields extending outward from the convective zones of stars.

Title: Present Knowledge, Problems and Questions concerning the
    Fibril Field of the Sun
Authors: Parker, E. N.
Bibcode: 1986ssmf.conf...13P
Altcode:
  This paper reviews some of the dilemmas presently posed by the magnetic
  fields of the sun, particularly the intense fibril state of the field
  at the visible surface. The fibril state has been conjectured to extend
  throughout the convective zone, although there is now evidence to the
  contrary. It is the agitation of the fibrils that supplies the energy
  to heat the active X-ray corona, presumably through dissipation in the
  thin current sheets arising from the intermixing of the footpoints. The
  coronal holes are presumed to be heated by Alfvén waves from the
  general agitation of fibrils. The active motion of the fibrils is a
  fundamental datum in the theory of the stellar corona, and it is to
  be hoped that the motions can be determined by observation in the next
  few years.

Title: Equilibrium of magnetic fields with arbitrary interweaving
    of the lines of force. I - Discontinuities in the torsion
Authors: Parker, E. N.
Bibcode: 1986GApFD..34..243P
Altcode:
  Consideration is given to the static force-free equilibrium of a
  magnetic field in which all of the lines of force connect without
  knotting between parallel planes. The field is formed by continuous
  deformation from an initial uniform field, and is conventiently
  described in terms of the scalar function psi, which is the stream
  function for the incompressible wrapping and interweaving of the
  lines of force. Local compression and expansion of the lines of force
  is described in terms of the scalar function Phi. Equilibrium in the
  field requires satisfaction of two independent equations which cannot be
  accomplished without the full freedom of both psi and Phi. It is shown
  that discontinuities in the torsional characteristics of the lines occur
  when psi is predetermined by an arbitrary pattern. Discontinuities in
  the winding pattern of the lines can lead to discontinuities in the
  associated current sheets.

Title: Equilibrium of magnetic fields with arbitrary interweaving
    of the lines of force. II. Discontinuities in the field.
Authors: Parker, E. N.
Bibcode: 1986GApFD..35..277P
Altcode:
  The surfaces of discontinuity (SDs) identified by Parker (1986) in
  the torsion of a force-free magnetic field in an infinitely conducting
  fluid contained betweeen two fixed boundary planes are characterized
  analytically. It is shown that field discontinuities (current sheets)
  occur whenever an SD terminates within the fluid or intersects with
  another SD, that intersections occur in most cases, and that the
  resulting current sheets are responsible for most field dissipation
  in highly conducting fluids. The astrophysical implications of these
  findings and a number of unresolved problems are discussed.

Title: The Magnetic Structure of Solar and Stellar Atmospheres
Authors: Parker, E. N.
Bibcode: 1986LNP...254..341P
Altcode: 1986csss....4..341P
  No abstract at ADS

Title: The magnetic structure of solar and stellar atmospheres
Authors: Parker, E. N.
Bibcode: 1986LNP...254..339P
Altcode:
  This paper summarizes the present state of knowledge and understanding
  of the remarkable structure of the magnetic field of the one star where
  the structure can be observed. The discussion emphasizes several of
  the outstanding puzzles in the form of the field above and below the
  visible surface and provides a brief survey of present theoretical
  understanding, so far as it goes. Emphasis is given to the basic
  observational and theoretical work that remains before we have what
  might be called a theory of solar and stellar activity.

Title: The Heliospheric Energy Source
Authors: Parker, E. N.
Bibcode: 1986ASSL..123...33P
Altcode: 1986shtd.symp...33P
  The solar wind and the heliosphere exist as a consequence of the heat
  input to the corona, particularly the coronal holes. The necessary
  energy input to coronal holes has been estimated to be 10 to the 6th
  erg/sq cm sec, requiring Alfven waves with rms fluid velocities of 100
  km/sec. Observational upper limits on coronal fluid velocities are of
  the order of 25 km/sec, which may not apply to the transparent coronal
  hole. Alternatively it has been suggested that coronal holes may be
  heated by agitation from neighboring active regions, suggesting that the
  vigor of a coronal hole depends upon its location. The Ulysses Mission
  will provide a direct comparison of the strength of the high speed wind
  from coronal holes at low latitude and coronal holes at high latitude,
  from which the nature of the presently unknown energy sources of the
  coronal holes and the resulting structure of the heliosphere may be
  better judged. The question is fundamental to the dynamics of the
  windspheres of all stars.

Title: The Future of Solar Physics
Authors: Parker, E. N.
Bibcode: 1985SoPh..100..599P
Altcode:
  The future of solar physics is founded on the existing fundamental
  unsolved problems in stellar physics. Thus, for instance, the physics
  of stellar interiors has been called into serious question by the very
  low-measured neutrino flux. The <SUP>71</SUP>Ga neutrino detection
  experiment is the next step in unravelling this mystery. If that
  experiment should find the expected neutrino flux from the basic p-p
  reaction in the Sun, then astrophysics is in a difficult situation,
  because the most likely explanation for the low neutrino flux found in
  the <SUP>37</SUP>Cl experiment would be an error in our calculation of
  the opacity or an error in our understanding of the elemental abundances
  in stellar interiors, with serious implications for present ideas on
  stellar structure and the age of the galaxy.

Title: Stellar fibril magnetic systems. II - Two-dimensional
    magnetohydrodynamic equations. III - Convective counterflow
Authors: Parker, E. N.
Bibcode: 1985ApJ...294...47P
Altcode:
  The dynamics of magnetic fibrils in the convective zone of a star
  is investigated analytically, deriving mean-field equations for
  the two-dimensional transverse motion of an incompressible fluid
  containing numerous small widely spaced circular cylinders. The
  equations of Parker (1982) are extended to account for the inertial
  effects of local flow around the cylinders. The linear field equation
  for the stream function at the onset of convection is then rewritten,
  neglecting large-scale heat transport, and used to construct a model
  of convective counterflow. The Kelvin impulse and fluid momentum,
  convective motion initiated by a horizontal impulse, and the effects
  of a viscous boundary layer are considered in appendices.

Title: Stellar Fibril Magnetic Systems - Part Three - Convective
    Counterflow
Authors: Parker, E. N.
Bibcode: 1985ApJ...294...57P
Altcode:
  The linearized equations of motion of a fibril magnetic field and
  the mean fluid motion through that field are used to illustrate the
  convective counterflow effect. The calculations show that starting
  from static equilibrium, a vertical impulse applied to a cluster of
  fibrils (represented by a cluster of parallel circular cylinders)
  may result in the fluid moving either upward or downward across
  the cluster, depending on the eccentricity of the cross section of
  the cluster and the strength of the aerodynamic drag coupling the
  fluid and fibrils. Specifically, a flattened cluster of fibrils,
  with a width in excess of twice the thickness, may be carried in the
  opposite direction from the initial applied impulse by the associated
  counter convective motion. It appears that this counterflow effect may
  operate in the upper few thousand km of the convective zone of the Sun,
  where it would play a role in suppressing the buoyant rise of magnetic
  flux tubes to the surface. Hence the convective counterflow may take
  an active part in controlling the emergence of flux tubes through the
  surface of a star like the Sun, perhaps regulating to some degree the
  form and general level of the activity of the star.

Title: The vector structure of active magnetic fields
Authors: Parker, E. N.
Bibcode: 1985svmf.nasa....7P
Altcode:
  Observations are needed to show the form of the strains introduced into
  the fields above the surface of the Sun. The longitudinal component
  alone does not provide the basic information, so that it has been
  necessary in the past to use the filamentary structure observed in
  H<SUB>alpha</SUB> to supplement the longitudinal information. Vector
  measurements provide the additional essential information to determine
  the strains, with the filamentary structure available as a check for
  consistency. It is to be expected, then, that vector measurements
  will permit a direct mapping of the strains imposed on the magnetic
  fields of active regions. It will be interesting to study the relation
  of those strains to the emergence of magnetic flux, flares, eruptive
  prominences, etc. In particular we may hope to study the relaxation
  of the strains via the dynamical nonequilibrium.

Title: Heating the corona of the sun.
Authors: Parker, E. N.
Bibcode: 1985rbcc.conf..299P
Altcode:
  The author suggests that coronal holes are heated by the dissipation of
  Alfvén waves. He also suggests that the active corona is heated by the
  random walk of the footpoints of the magnetic field, causing cumulative
  small-scale strains in the magnetic field. These quasi-static strains
  dissipate as a consequence of the absence of magnetostatic equilibrium
  for random topological distortions of the field, producing current
  sheets and neutral point reconnection.

Title: Equilibrium of magnetic fields with arbitrary interweaving
    of the lines of force i. discontinuities in the torsion
Authors: Parker, E. N.
Bibcode: 1985GApFD..34..243P
Altcode:
  This paper considers the static force-free equilibrium V×B=B of a
  magnetic field in which all of the lines of force connect without
  knotting between parallel planes. The field is formed by continuous
  deformation from an initial uniform field, and is conveniently
  described in terms of the scalar function , which is effectively the
  stream function for the incompressible wrapping and interweaving of
  the lines of force, and the scalar function , which describes the
  local compression and expansion. Equilibrium requires satisfaction
  of two independent equations (the third equation defines ), which
  cannot be accomplished without the full freedom of both functions
  and . It is shown by integration along the characteristics of the
  equilibrium equations that, when is predetermined by an arbitrary
  winding pattern, there appear discontinuities in . Discontinuities in
  have discontinuities in the field (i.e. current sheets) associated with
  them. We expect such discontinuities to be produced in the magnetic
  fields extending outward from the convecting surfaces of the cooler
  stars.

Title: Solar Physics as Related to Stellar Physics
Authors: Parker, E. N.
Bibcode: 1985spit.conf...13P
Altcode:
  No abstract at ADS

Title: The vector structure of active magnetic fields.
Authors: Parker, E. N.
Bibcode: 1985NASCP2374....7P
Altcode:
  Observations are needed to show the form of the strains introduced into
  the fields above the surface of the sun. The longitudinal component
  alone does not provide the basic information, so that it has been
  necessary in the past to use the filamentary structure observed in
  Hα to supplement the longitudinal information. Vector measurements
  provide the additional essential information to determine the strains,
  with the filamentary structure available as a check for consistency. It
  is to be expected, then, that vector measurements will permit a direct
  mapping of the strains imposed on the magnetic fields of active regions.

Title: Magnetic Buoyancy and the Flux Ejection Effect in Stellar
    Dynamos
Authors: Parker, E. N.
Bibcode: 1985spit.conf..360P
Altcode:
  No abstract at ADS

Title: The Rapid Dissipation of Stellar Magnetic Fields and the
    Production of X-Ray Coronas
Authors: Parker, E. N.
Bibcode: 1985spit.conf..925P
Altcode:
  No abstract at ADS

Title: Magnetic Fields in the Radiative Interior of Stars - Part Two -
    Forced Convection and the 7LI Abundance
Authors: Parker, E. N.
Bibcode: 1984ApJ...286..677P
Altcode:
  Magnetic fields of various forms, and of strengths ranging up to
  5×10<SUP>8</SUP>gauss, in the radiative core of the Sun have been
  hypothesized by various authors. This paper points out that the
  thermal shadows of magnetic inhomogeneities in the radiative core
  cause vertical mixing of fluid, with possible consequences for the
  <SUP>7</SUP>Li abundance in the Sun. Magnetic fields of the order
  of 4×10<SUP>5</SUP>gauss with scales of 3×10<SUP>4</SUP>km are
  sufficient to provide the partial depletion of <SUP>7</SUP>Li inferred
  from observation. It is found that the rms field in the outer radiative
  zone cannot much exceed 4×10<SUP>5</SUP>gauss.

Title: Magnetic fields in the radiative interior of stars. I Thermal
    shadows and forced convection.
Authors: Parker, E. N.
Bibcode: 1984ApJ...286..666P
Altcode:
  It is pointed out that magnetic fields in the radiative interior of a
  star cause a slight reduction in the gas pressure, by a fraction of the
  order of B<SUP>2</SUP>/8πp. The effect is a proportionate reduction in
  the opacity and an increase in the effective heat transport coefficient,
  so that magnetic inhomogeneities cast thermal shadows in the general
  outflow of radiant energy. The shadows involve horizontal temperature
  gradients, forcing convective circulation in the otherwise stably
  stratified radiative zone. The associated vertical mixing may have
  important consequences for the thermonuclear burning of <SUP>7</SUP>Li
  in the outer envelope of the star.

Title: The rapid dissipation of magnetic fields with internal strains.
Authors: Parker, E.
Bibcode: 1984JRASC..78..205P
Altcode:
  No abstract at ADS

Title: Stellar fibril magnetic systems. I - Reduced energy state
Authors: Parker, E. N.
Bibcode: 1984ApJ...283..343P
Altcode:
  The remarkable fibril structure of the magnetic fields at the
  surface of the sun (with fibrils compressed to 1,000-2,000 gauss)
  lies outside existing statistical theories of magnetohydrodynamic
  turbulence. The total energy of the fibril field is enhanced by a
  factor of more than 100 above the energy for the mean field in a
  continuum state. The magnetic energy density within a fibril is of
  the order of 100 times the local kinetic energy density, so that
  no simple application of equipartition principles is possible. It
  is pointed out that the total energy of the atmosphere (thermal +
  gravitational + magnetic) is reduced by the fibril state of the field
  by avoiding the magnetic inhibition of the convective overturning,
  suggesting that the formation of the observed intense fibril state
  may be in response to the associated energy reduction. Calculation
  of the minimum total energy of a polytropic atmosphere permeated by
  magnetic fibrils yields theoretical fibril fields of the order of 1-5
  kilogauss when characteristics appropriate to the solar convective
  zone are introduced, in rough agreement with the actual fields of 1-2
  kilogauss. The polytrope model, although crude, establishes that a
  large reduction in total energy is made possible by the fibril state.

Title: Magnetic buoyancy and the escape of magnetic fields from stars
Authors: Parker, E. N.
Bibcode: 1984ApJ...281..839P
Altcode:
  Magnetic buoyancy causes the azimuthal magnetic fields of stars to
  rise rapidly to the surface, from where they are generally assumed
  to escape freely into space. However, a closer look at the problem
  reveals the simple fact that disengagement of the field from the gas,
  and escape into space, require a convoluted field configuration,
  producing neutral point reconnection of the flux in the tenuous gas
  above the surface of the star. Only that flux which reconnects can
  escape. <P />Recent observations of the magnetic fields emerging
  through the surface of the Sun show that even at sunspot maximum the
  gaps in longitude between bipolar magnetic regions are so wide as to
  limit severely the reconnection between regions. We suggest from the
  observations that no more than perhaps 3% of the flux that is observed
  to emerge through the surface is able to reconnect and escape. Hence
  the surface of the Sun approximates to an impenetrable barrier rather
  than an open surface, with quantitative consequences for theoretical
  dynamo models. <P />Recent observations of the retraction of bipolar
  fields at the end of their appearance at the surface suggest active
  dynamical control by the convection beneath the surface.

Title: Depth of origin of solar active regions
Authors: Parker, E. N.
Bibcode: 1984ApJ...280..423P
Altcode:
  Observations show that the individual bipolar magnetic regions on
  the sun remain confined during their decay phase, with much of the
  magnetic field pulling back under the surface, in reverse of the
  earlier emergence. This suggests that the magnetic field is held on
  a short rein by subsurface forces, for otherwise the region would
  decay entirely by dispersing across the face of the sun. With the
  simple assumption that the fields at the surface are controlled from
  well-defined anchor points at a depth h, it is possible to relate the
  length l of the bipolar region at the surface to the depth h, with
  h about equal to l. The observed dimensions l about equal to 100,000
  km for normal active regions, and l about equal to 10,000 km for the
  ephemeral active regions, indicate comparable depths of origin. More
  detailed observational studies of the active regions may be expected
  to shed further light on the problem.

Title: The role of flux ejection in stellar dynamos
Authors: Parker, E. N.
Bibcode: 1984ApJ...276..341P
Altcode:
  Magnetic buoyancy causes the magnetic field in the convective zone of a
  star to escape through the surface in times short compared to the period
  of the magnetic cycle. The sun serves as a prototype, where fields of
  100-1000 gauss or stronger are present in the convective zone, as part
  of the 22 year magnetic cycle. The theoretical alpha-omega dynamo effect
  cannot cope with the rapid escape (in a year or so) because increasing
  the rate of generation of field serves also to shortern the period, to
  a value comparable to the escape time. It is suggested that the flux
  ejection dynamo effect may be operating in the deep convective zone,
  where the cyclonic rotation of the convective cells may be as large
  as 180 deg. If so, then the flux ejection effectively opposes the
  buoyant rise. It is shown that the net effect of flux ejection in the
  lower convective zone, and unopposed buoyancy in the upper convective
  zone, permits the alpha-omega-dynamo effect to carry on the cyclic
  regeneration of the magnetic field much as in the absence of either
  buoyancy or flux ejection, except that the magnetic field is strongly
  concentrated against the bottom of the convective zone. It is suggested
  that the lower and upper regions of the dynamo may be related to the
  normal and ephermeral active regions, as has already been suggested
  by others on the basis of the observed distinctions in distribution.

Title: Magnetic Reconnection and Magnetic Activity
Authors: Parker, E. N.
Bibcode: 1984mrsl.conf...32P
Altcode:
  No abstract at ADS

Title: Magnetic reconnection and magnetic activity
Authors: Parker, E. N.
Bibcode: 1984GMS....30...32P
Altcode: 1984GMS.........32P
  A large-scale magnetic field extending through a highly conducting
  tenuous fluid may become distorted on a small scale as a consequence
  of slow small-scale shuffling of the magnetic lines of force at
  the boundaries of the tenuous fluid. Any slow wrapping and winding
  introduced at the boundaries is distributed along the field (at
  the Alfven speed). It is a curious and little-known fact that such
  wrapping and winding possesses no static equilibrium (except for a
  set of solutions of extreme symmetry). The result is neutral-point
  reconnection of the strains in the field, rapidly dissipating the
  wrapping and winding. It is suggested that this is the principal cause
  of the extreme heating that produces the active corona of the sun and
  other stars. The shuffling of the footpoints of the magnetic field in
  the photospheric turbulence introduces small-scale wrapping and twisting
  into the coronal loops. The work done by the turbulence in twisting
  the fields is dissipated within a matter 10-20 hours by neutral-point
  reconnection, introducing heat into the corona at a rate of about
  10 Mergs/sq cm sec for photospheric turbulence of 0.5 km/sec. It is
  suggested that this is the basic cause of the X-ray corona.

Title: Heating the Corona of the Sun
Authors: Parker, E. N.
Bibcode: 1984rcch.conf..299P
Altcode:
  No abstract at ADS

Title: Galactic magnetic fields and magnetic monopoles.
Authors: Parker, E. N.
Bibcode: 1984mono.conf..125P
Altcode:
  No abstract at ADS

Title: Alfvén waves in a thermally stratified fluid.
Authors: Parker, E. N.
Bibcode: 1984GApFD..29R...1P
Altcode:
  The propagation of Alfvén waves along a uniform horizontal field in a
  highly conducting incompressible fluid, subject to the convective forces
  produced by a uniform vertical temperature gradient, is treated in a
  Boussinesq approximation. It is shown that there are exact solutions
  with large amplitude but restricted form.

Title: Alfvén waves in a thermally stratified fluid.
Authors: Parker, E. N.
Bibcode: 1984GApFD..29Q...1P
Altcode:
  The propagation of Alfvén waves along a uniform horizontal field in
  a highly conducting incompressible fluid, subject to the convective
  forces produced by a uniform vertical temperature gradient, is treated
  in a Boussinesq approximation. It is shown that there are exact
  solutions with large amplitude but restricted form. Their restricted
  form means that an arbitrary disturbing force produces other motions
  as well as Alfvén waves. An arbitrary initial disturbance of small
  amplitude produces waves whose state of polarization varies along the
  direction of propagation. For large amplitudes, however, any mixtures
  of polarization states causes scattering into new modes.

Title: Alfven waves in a thermally stratified fluid
Authors: Parker, E. N.
Bibcode: 1984GApFD..29....1P
Altcode:
  The properties of Alfven waves propagating along a uniform horizontal
  field in a highly conducting incompressible medium in the presence
  of strong convective instability are examined in the Boussinesq
  approximation. In particular, it is sought to determine whether
  there are exact solutions to the dynamical equations in the presence
  of convective forces. It is shown that a class of exact solutions
  of arbitrary amplitude, but of limited form, which may be of some
  physical interest, does exist. For large amplitudes, any mixtures of
  polarization states are shown to cause scattering into new modes.

Title: Direct coronal heating from dissipation of magnetic field.
Authors: Parker, E. N.
Bibcode: 1983NASCP.2280..23P
Altcode: 1983sowi.conf...23P
  The visible corona of the Sun appears to be heated by direct dissipation
  of magnetic fields. The magnetic fields in the visible corona are
  tied at both ends to the photosphere where the active convection
  continually rotates and shuffles the footpoints in a random pattern. The
  twisting and wrapping of flux tubes about each other produce magnetic
  neutral sheets in a state of dynamical nonequilibrium such that the
  current sheets become increasingly concentrated with the passage of
  time. Dissipation of the high current densities takes place regardless
  of the high electrical conductivity of the fluid. The convection on
  the feet of the lines of force at the surface of the Sun goes directly
  (within a matter of 10 to 20 hours) into heat in the corona. The rate
  of doing work seems adequate to supply the necessary 10 to the 7th
  power ergs/square cm. sec for the active corona.

Title: Invited Talk (Solar Division): "Theoretical MHD Structure of
    Stellar Atmospheres, and Close Observations of the Sun"
Authors: Parker, Eugene
Bibcode: 1983BAAS...15..950P
Altcode:
  No abstract at ADS

Title: Magnetic fields in the cosmos
Authors: Parker, E. N.
Bibcode: 1983SciAm.249b..44P
Altcode: 1983SciAm.249...44P; 1983SciAm.249...36P
  Descriptive models for the dynamo processes that generate magnetic
  fields around celestial objects are reviewed. Magnetic fields are
  produced, along with an electric current, when a conductor is moved
  perpendicularly through a magnetic field, so long as the resulting
  current is fed back into the conductor to amplify the current and
  field. In MHD theory, the lines of force of the magnetic field
  travel with the conducting fluid. A weak current or field must be
  present initially to generate the field. Planets have molten cores
  and stars have ionized gases to act as the conductors, and all space
  has sufficient gas with free electrons. The rotations of the planets,
  stars, and galaxy enhance the magnetic fields. Convective patterns
  have been characterized in the earth's molten core because of anomalies
  observed in the magnetic field at the surface. It has been shown that
  the faster a planet rotates, the more powerful its magnetic field
  is. However, fluid motions will produce fields only if the fluid motion
  is helical. The exact mechanism in stars could be primordial magnetism
  trapped during formation. However, in galaxies, the Biermann battery
  effect, wherein free electrons move along the surfaces of stars,
  could create enough of a field for the amplification process to proceed.

Title: Up to a frontier of astrophysics
Authors: Parker, E. N.
Bibcode: 1983Natur.303..262P
Altcode:
  No abstract at ADS

Title: Magnetic neutral sheets in evolving fields. I - General theory.
Authors: Parker, E. N.
Bibcode: 1983ApJ...264..635P
Altcode:
  The problem of the hydrostatic equilibrium of a large-scale magnetic
  field embedded in a fluid with infinite electrical conductivity
  is considered. It is pointed out that a necessary condition for
  static equilibrium is the invariance of the small-scale pattern in
  the field along the large-scale direction. A varying topological
  pattern implies that no fluid pressure distribution exists for which
  the field is everywhere static. Magnetic neutral sheets form, and
  dynamical reconnection of the field takes place. It is shown here that
  the invariance is also a sufficient condition for the existence of a
  fluid pressure distribution producing static equilibrium. Even in the
  simplest cases, however, the requirements on the fluid pressure are
  extreme and, a priori, are unlikely. It is concluded that almost all
  twisted flux tubes packed together produce dynamical nonequilibrium
  and dissipation of their twisting. This is the basic effect underlying
  the long-standing conjecture that the shuffling of the footpoints of
  the bipolar magnetic fields in the sun is responsible for heating the
  active corona. Attention is then given to the consequences of this
  general dynamical dissipation in the magnetic fields that produce the
  active corona of the sun. The footpoints of the field are continually
  manipulated by the subphotospheric convection in such a way that the
  lines of force are continually wrapped and rotated about one another.

Title: Magnetic Neutral Sheets in Evolving Fields - Part Two -
    Formation of the Solar Corona
Authors: Parker, E. N.
Bibcode: 1983ApJ...264..642P
Altcode:
  It is shown in the previous paper that whenever twisted flux tubes
  are bundled together, they are subject to dynamical nonequilibrium
  and internal neutral point reconnection, causing rapid dissipation
  of their torsion. In the present paper we explore the consequences
  of this general dynamical dissipation in the magnetic fields that
  produce the active corona of the Sun. The footpoints of the field are
  continually manipulated by the subphotospheric convection, so that the
  lines of force are continually wrapped and rotated about each other. The
  dynamical dissipation of the wrapping and rotation transfers the work
  done on the footpoints directly into heat in the corona, at a rate
  estimated to be of the order of 10<SUP>7</SUP> ergs cm<SUP>-2</SUP>
  s<SUP>-1</SUP>. The effect appears to be the principal source of heat to
  the visible corona. <P />This general picture implies that all magnetic
  fields extending outward from convecting astronomical bodies produce
  intense heating of the tenuous outer atmospheres of those bodies, in
  general agreement with the observed fact of the universal activity of
  stars and galaxies.

Title: Generation of solar magnetic fields. I. II
Authors: Parker, E. N.
Bibcode: 1983ASSL..104..101P
Altcode: 1983stp..conf..101P
  Attention is given to those magnetic field properties which allow
  the fields to destroy themselves rapidly, thereby producing solar,
  stellar and geomagnetic activity. Magnetic fields actively figure in
  the production of flares, plages, eruptions and streamers. The existence
  of magnetic fields in other stars is inferred from the X-rays that can
  be observed to radiate from them. In the second part of this paper,
  the discussion in the first part of the generation of magnetic fields
  from the motion of conducting fluids is further developed through
  the proposal of the 'short, sudden' idealization, and quick bursts
  of turbulence during which any degree of twisting and rotation can be
  accomplished are introduced. After these quick bursts of motion, the
  fluid is held motionless so that small scale irregularities subside,
  leaving a smooth, average and large scale state. This cycle is repeated
  at time intervals tau, producing the dynamo equations for the mean
  vector potential.

Title: The propagation of torsion along flux tubes subject to
    dynamical nonequilibrium
Authors: Parker, E. N.
Bibcode: 1983GApFD..24..245P
Altcode:
  The dynamical nonequilibrium of close-packed flux tubes is driven by
  the torsion in the individual tubes so that, wherever tubes with the
  same sense of twisting come into contact, there is reconnection of their
  azimuthal field components. The reconnection consumes the local torsion,
  causing the propagation of torsional Alfven waves into the region
  from elsewhere along the tubes. The formal problem of the propagation
  of the torsion along twisted flux tubes is presented and some of the
  basic physical properties worked out in the limit of small torsion. It
  is pointed out that in tubes with finite twisting the propagation of
  torsional Alfven waves can be a more complicated phenomenon. Application
  to the sun suggests that the propagation of torsion from below the
  visible surface up into the corona is an important energy supply to
  the corona for a period of perhaps 10-20 hours after the emergence
  of the flux tubes through the surface of the sun, bringing up torsion
  from depths of 104km or more. Torsion is continually supplied by the
  manipulation and shuffling of the field by the convection, of course.

Title: Heating of the outer solar atmosphere. I. II
Authors: Parker, E. N.
Bibcode: 1983ASSL..104..129P
Altcode: 1983stp..conf..129P
  The magnetic field coming up through the surface of the sun is
  responsible for the solar activity that heats the outer solar
  atmosphere. The field behaves in ways that are unexpected and little
  understood. Beckers and Schroeter (1969) found that the field of the sun
  has a fibril structure made up of separate, compressed flux tubes having
  fields of 1000-2000 G and 100-500 km diameters. Immediately above the
  solar surface, the field expands to fill the available volume. Nothing
  is known about the state beneath the surface of the sun. Attention is
  presently given to the state of knowledge on the heating of the corona
  as well as to a model for magnetic merging. In the second part of this
  presentation, the mutual wrapping and shuffling of the lines of force
  of a bipolar magnetic field above the photosphere and the structure
  of the cross section through a flux tube bundle are discussed.

Title: Absence of equilibrium among close-packed twisted flux tubest
Authors: Parker, E. N.
Bibcode: 1983GApFD..23...85P
Altcode:
  The general absence of static equilibrium of a close-packed array
  of parallel twisted flux tubes in a highly conducting medium
  is demonstrated by showing that the solutions to the equilibrium
  equation V2A+4P'(A) = 0 do not generally preserve the flux connections
  around each twisted tube as the functional form of P(A) is varied. A
  special constraint on the variation of P(A) is introduced, then,
  by the requirement that the flux connections be preserved. Hence we
  conclude that while a particular array of twisted tubes, described
  by the internal circulation of flux within each tube, may have an
  equilibrium for some suitably chosen functional form P(A), the array
  is generally in a state of nonequilibrium for lack of that precise
  functional form in the real world.

Title: The hydrodynamics of magnetic nonequilibrium
Authors: Parker, E. N.
Bibcode: 1983GApFD..24...79P
Altcode:
  Because the dynamical nonequilibrium of closely packed twisted flux
  tubes is essentially the problem of two-dimensional MHD turbulence,
  the extensive literature on two-dimensional turbulence represents
  the hydrodynamics of magnetic nonequilibrium. Many features of
  the turbulence can conversely be understood as a consequence of the
  dynamical nonequilibrium. Attention is presently given to the dynamics
  of the strong fluid jets, issuing from reconnection points, that are
  exhibited by numerical simulations of two-dimensional turbulence. Simple
  examples are given which show that the uniformity of jet width
  observed is a consequence of the form of the pressure of the magnetic
  fields between which the jets are confined. The general hydrodynamics
  of a layer of fluid confined by steady pressures is reducible to a
  quadrature, so that a variety of effects may be considered, including
  gravitation. The dissipation of the solar corona is discussed.

Title: Cosmic magnetic fields. Their origin and manifestation. In
    two parts.
Authors: Parker, E.
Bibcode: 1983cmft.book.....P
Altcode:
  No abstract at ADS

Title: Generation of Solar Magnetic Fields II
Authors: Parker, Eugene N.
Bibcode: 1983ASSL..104..113P
Altcode:
  No abstract at ADS

Title: Heating of the Outer Solar Atmosphere II
Authors: Parker, Eugene N.
Bibcode: 1983ASSL..104..139P
Altcode:
  No abstract at ADS

Title: The rapid dissipation of magnetic fields in highly conducting
    fluids
Authors: Parker, E. N.
Bibcode: 1982GApFD..22..195P
Altcode:
  This paper treats the dynamical conditions that obtain when long
  straight parallel twisted flux tubes in a highly conducting fluid
  are packed together in a broad array. It is shown that there is
  generally no hydrostatic equilibrium. In place of equilibrium there
  is a dynamical nonequilibrium, leading to neutral point reconnection
  and progressive coalescence of neighboring tubes (with the same sense
  of twisting), forming tubes of larger diameter and reduced twist. The
  magnetic energy in the twisting of each tube declines toward zero,
  dissipated into small-scale motions of the fluid and thence into
  heat. The physical implications are numerous. For instance, it has been
  suggested that the subsurface magnetic field of the sun is composed
  of close-packed twisted flux tubes. Any such structures are short
  lived, at best. The footpoints of the filamentary magnetic fields
  above bipolar magnetic regions on the sun are continually shuffled and
  rotated by the convection, so that the fields are composed of twisted
  rubes. The twisting and mutual wrapping is converted directly into
  fluid motion and heat by the dynamical nonequilibrium, so that the work
  done by the convection of the footpoints goes directly into heating
  the corona above. This theoretical result is the final step, then, in
  understanding the assertion by Rosner, Tucker, and Valana, and others,
  that the observed structure of the visible corona implies that it is
  heated principally by direct dissipation of the supporting magnetic
  field. It is the dynamical nonequilibrium that causes the dissipation,
  in spite of the high electrical conductivity. It would appear that
  any bipolar magnetic field extending upward from a dense convective
  layer into a tenuous atmosphere automatically produces heating, and
  a corona of some sort, in the sun or any other convective star.

Title: Magnetic monopoles and the survival of galactic magnetic fields
Authors: Turner, Michael S.; Parker, E. N.; Bogdan, T. J.
Bibcode: 1982PhRvD..26.1296T
Altcode:
  The most stringent, mass-independent limit on the flux of magnetic
  monopoles is based upon the survival of the galactic magnetic
  fields, the so-called "Parker limit": F&lt;~10<SUP>-16</SUP>
  cm<SUP>-2</SUP>sr<SUP>-1</SUP>sec<SUP>-1</SUP>. We reexamine this limit,
  taking into account the monopole's mass and velocity distribution,
  and the observed structure of the galactic magnetic field. We derive
  flux limits which depend upon the monopole's mass and velocity,
  and the strength, coherence length, and regeneration time of the
  galactic magnetic field. The largest monopole flux consistent with
  both the survival of the galactic magnetic field and the bounds from
  the mass density contributed by monopoles is F~=10<SUP>-12</SUP>
  cm<SUP>-2</SUP>sr<SUP>-1</SUP>sec<SUP>-1</SUP>, arising for monopoles
  of mass ~= 10<SUP>19</SUP> GeV with velocity ~=3×10<SUP>-3</SUP>c
  which cluster with the Galaxy. An observed flux greater than this
  would have profound implications for our understanding of the galactic
  magnetic field, and we briefly explore some exotic possibilities. Of
  course, this bound is not applicable to a local source (e.g., the Sun,
  atmospheric cosmic-ray production, etc.).

Title: The Flux Ejection Dynamo with Small Diffusivity - Part One -
    Basic Properties
Authors: Parker, E. N.
Bibcode: 1982Ap&SS..85..167P
Altcode:
  The flux ejection dynamo in an infinitely broad convective layer
  of finite depth is treated in the limit of large electrical
  conductivity. The upper surface of the convective layer is open
  to empty space while the lower surface is closed to the passage of
  fluid and field. An idealized convective overturning is employed,
  permitting an exact description of the symmetry and distribution of
  the magnetic field carried with the fluid. Escape of the reverse field
  through the free surface restores the initial vertical distribution
  of mean field and adds a thin sheet of flux in the initial direction
  across the bottom of the convective layer. The total flux in the mean
  horizontal field grows linearly with the number of convective cycles. We
  discuss the boundary conditions to be applied to an astronomical body
  with the flux ejection dynamo operating at its surface. It is pointed
  out that if there were a flux ejection dynamo operating in the Sun,
  the implications of the magnetic bipolar regions emerging through the
  surface would be the opposite of the usual.

Title: The Flux Ejection Dynamo with Small Effusivity - Part Two -
    Illustrative Examples
Authors: Parker, E. N.
Bibcode: 1982Ap&SS..85..183P
Altcode:
  A number of examples are worked out to illustrate the consequences
  of reverse flux ejection from the surface of a convective layer of
  conducting fluid. Generally the reverse flux ejection has the opposite
  effect of magnetic buoyancy, tending to bury the fields rather than
  bringing them through the surface. Even a weak flux ejection effect
  prevents the excape of magnetic field through the surface. Reverse
  flux ejection at the surface of an αω-dynamo profoundly alters
  the character of the solutions of the dynamo equations. Altogether,
  flux ejection serves to obscure the interpretation of magnetic
  observations. The outstanding problem now is to determine under what
  circumstances there exists cyclonic convection with rotations in excess
  of ±1/2π in the rising columns of fluid. Negative turbulent diffusion
  is expected to be a close companion of the flux ejection effect.

Title: The Dynamics of Fibril Magnetic Fields - Part Four - Trapping
    in Closed Convective Rolls
Authors: Parker, E. N.
Bibcode: 1982ApJ...256..746P
Altcode:
  The equations of motion for a slender, buoyant flux tube extending
  horizontally along a closed convective roll are solved to illustrate
  the motion of the flux tube relative to the fluid. The principal effect
  of the buoyant rise u of the flux tube is to offset the path of the
  tube (which remains closed) from the closed circulation pattern of
  the fluid. Further investigation shows that an upward decrease of ρ
  u causes the position of the tube to spiral inward to the dynamical
  equilibrium point where the convective downdraft is equal to the buoyant
  rise. Any variation of the convective velocity along the length of the
  roll has the same effect, so that flux tubes, or fibrils, are stably
  trapped in any closed convective flow that exceeds u. <P />The effect
  may be operative in the convective zone of the Sun and other stars
  where the meridional circulation is larger than the rate of rise of
  the standard fibril. Even if there is no long-term trapping of the
  field, the position of emergence of flux tubes at the surface of the
  Sun may be widely removed from their birthplace. A number of examples
  are given to illustrate the possibilities.

Title: The dynamics of fibril magnetic fields. III - Fibril
    configurations in steady flows.
Authors: Parker, E. N.
Bibcode: 1982ApJ...256..736P
Altcode:
  The present investigation has the objective to provide an illustration
  of the equilibrium form of a hypothetical fibril field beneath the
  surface of the sun. Equilibrium fibril paths in static and moving
  atmospheres are considered. The provided examples are related to
  horizontal flows in an atmosphere in which the two anchor points
  of the arched fibril lie along the flow direction relative to each
  other. A brief introduction to the subject of the motion of horizontal
  fibrils in convective rolls is also presented, taking into account
  some implications for the sun. The equations of motion for a slender,
  buoyant flux tube extending horizontally along a closed convective
  roll are solved to illustrate the motion of the flux tube relative to
  the fluid, and attention is given to theoretical possibilities for the
  escape of flux tubes from a large horizontal convective roll in the sun.

Title: The Dynamics of Fibril Magnetic Fields - Part Two - the Mean
    Field Equations
Authors: Parker, E. N.
Bibcode: 1982ApJ...256..302P
Altcode:
  A variety of scenarios for the origin and activity of magnetic fields in
  the convective zone of the Sun have been put forth in recent years. In
  particular, a number of authors have urged that the magnetic field
  is in a generally fibril state, much as observed at the surface,
  with a variety of suggestions as to the consequences. The present
  paper works out the mean field equations for intense thin fibrils of
  fixed cross section under the assumption of some significant local
  ordering. The aim is to establish to what degree new effects may arise
  as a result of the fibril state. It is shown that the fibril state of
  a mean field B enhances the tension in the field and the buoyancy of
  the field by the compression factor m of the field in the individual
  fibrils. New qualitative effects appear in the slip velocity u of the
  fibrils through the ambient fluid and in the neutral point reconnection
  of neighboring fibrils. Some of the novel features are illustrated in
  later papers in this series. One of the most important consequences is
  the simplification of the theory of turbulent diffusion by eliminating
  the looping and tangling that arises when a continuum field is carried
  in a chaotic turbulent flow. We have been unable to find any effects
  that would admit of a new concept for the origin of the solar magnetic
  fields.

Title: The dynamics of fibril magnetic fields. I - Effect of flux
    tubes on convection.
Authors: Parker, E. N.
Bibcode: 1982ApJ...256..292P
Altcode:
  Observations have established the general fibril state of the magnetic
  field at the visible surface of the sun. This extraordinary state of the
  field, in separate intense flux tubes, implies that the convection has
  a relatively permanent, closed topology, in spite of the large Reynolds
  number. This paper explores some of the effects of the separate flux
  tubes on the convective motions, generally pushing the convective
  cells toward aligning their downdrafts with the flux tubes so as to
  minimize the dissipation.

Title: Compression of magnetic field in a viscous boundary layer.
Authors: Parker, E. N.
Bibcode: 1982SoPh...77....3P
Altcode:
  Galloway, Proctor, and Weiss have shown by numerical experiment that
  the magnetic field extending across a convective cell in a highly
  conducting viscous fluid may be concentrated into sheets with energy
  density B<SUP>2</SUP>/8π larger than the kinetic energy density
  1/2ϱv<SUP>2</SUP> of the convection by a factor (v/η)<SUP>1/2</SUP>
  or more. This paper employs conventional boundary layer theory for high
  Reynolds number to provide a simple analytical example illustrating
  this remarkable effect of field concentration.

Title: The flux ejection dynamo effect
Authors: Parker, E. N.
Bibcode: 1982GApFD..20..165P
Altcode:
  The mean-field effects of cyclonic convection become increasingly
  complex when the cyclonic rotation exceeds ½-. Net helicity is not
  required, with negative turbulent diffusion, for instance, appearing in
  mirror symmetric turbulence. This paper points out a new dynamo effect
  arising in convective cells with strong asymmetry in the rotation
  of updrafts as against downdrafts. The creation of new magnetic flux
  arises from the ejection of reserve flux through the open boundary of
  the dynamo region. It is unlike the familiar -effect in that individual
  components of the field may be amplified independently. Several formal
  examples are provided to illustrate the effect. Occurrence in nature
  depends upon the existence of fluid rotations of the order of in the
  convective updrafts. The flux ejection dynamo may possibly contribute
  to the generation of field in the convective core of Earth and in the
  convective zone of the sun and other stars.

Title: Photospheric flow and stellar winds
Authors: Parker, E. N.
Bibcode: 1981ApJ...251..266P
Altcode:
  The effect of the photospheric outflow on the expansion of the strongly
  bound coronas of dwarf main-sequence stars is examined. The extended
  temperatures of the strongly bound coronas cause the stars to expand
  and form tenuous stellar winds, with a slight mean upward motion
  of the gas in the photosphere to replenish the mass loss through the
  coronal expansion. A formal solution of the time-dependent hydrodynamic
  equations illustrates the effects of the photospheric velocity at large
  distances, and the effect of blocking the upward flow in the photosphere
  is calculated using the sun as an example. Results indicate that the
  expansion of a strongly bound corona is insensitive over historical
  time scales to the small outflow of gas in the photosphere.

Title: The hydromagnetic dynamo
Authors: Parker, E. N.
Bibcode: 1981ESASP.161...23P
Altcode: 1981plas.work...23P
  No abstract at ADS

Title: The non-equilibrium of magnetic fields
Authors: Parker, E. N.
Bibcode: 1981ESASP.161...31P
Altcode: 1981plas.work...31P
  No abstract at ADS

Title: The magnetohydrodynamic dynamo
Authors: Parker, E. N.
Bibcode: 1981plap.rept...23P
Altcode:
  A mechanism for the maintenance of the magnetic fields of planets,
  stars, and galaxies is postulated. It appears that cyclonic convection
  and nonuniform rotation within the liquid metal cores of planets,
  the convective zones of stars, and the gaseous disks of galaxies
  provide an efficient dynamo mechanism for the production of these
  fields. The dominant field within the body is azimuthal, produced
  by nonuniform rotation from the poloidal field. The interaction of
  cyclonic convection within the azimuthal field produces loops of flux
  in meridional planes whose net effect is a meridional circulation of
  field in the same sense as the original poloidal field. Both stationary
  and oscillatory fields can be generated in this way.

Title: The nonequilibrium of magnetic fields
Authors: Parker, E. N.
Bibcode: 1981plap.rept...31P
Altcode:
  The more subtle properties of magnetic fields which create
  nonequilibrium and lead to vigorous activity in otherwise sluggish
  gas-field systems are evaluated for gross hydromagnetic effects. The
  gentle manipulation of magnetic fields on a large scale leads to the
  production of small scale variations and discontinuities, providing
  intense dissipation of magnetic field in a large scale system. A
  magnetic field embedded in a conducting fluid possesses a static
  equilibrium only if the topology of the lines of force is suitably
  invariant along the direction of the field. When the field does not
  possess the necessary invariance, it is subject to internal neutral
  point reconnection. The magnetic fields of most stars suffer such
  nonequilibrium, and consequent enhanced dissipation, providing an
  important source of heat in their outer atmospheres.

Title: The Dissipation of Inhomogeneous Magnetic Fields and the
    Problem of Coronae - Part Two - the Dynamics of Dislocated Flux
Authors: Parker, E. N.
Bibcode: 1981ApJ...244..644P
Altcode:
  When any of the flux tubes that collectively make up a magnetic field
  continuum is dislocated and misaligned relative to the rest of the
  field, there is a dynamical steepening of field gradients. Consequently,
  there is rapid dissipation of the dislocated field no matter how
  large the electrical conductivity of the medium. This paper presents
  some formal illustrations of local conditions along a misaligned flux
  tube, showing the simultaneous onset of diffusion, fluid motion, and
  hydromagnetic wave propagation. The examples show that the total effect
  is complicated and subject only to estimation, rather than formal
  calculation, at the present time. <P />We suggest that dislocation
  dissipation occurs in the magnetic fields of active regions on the
  Sun, contributing to the enhanced corona. Estimates of the dislocation
  dissipation in the active corona are carried out based on the observed
  properties of active coronal arches and filaments. The estimates show
  that the dissipation may contribute a significant portion of the coronal
  heating. It is pointed out that dislocation dissipation must occur in
  the active terrestrial magnetosphere and in the active gaseous disk of
  the Galaxy, although we make no attempt at a quantitative assessment
  of the rates.

Title: The dissipation of inhomogeneous magnetic fields and the
    problem of coronae. I - Dislocation and flattening of flux tubes. II -
    The dynamics of dislocated flux
Authors: Parker, E. N.
Bibcode: 1981ApJ...244..631P
Altcode:
  Attention is given to the dynamical dissipation arising in a magnetic
  field extending up through a tenuous atmosphere when an elemental
  flux tube in the field (1) is displaced from its equilibrium position
  and/or (2) is inflated by an internal fluid pressure different from
  the external fluid pressure. It is pointed out that as a consequence
  the tension in the lines of force of the ambient field flattens the
  dislocated tube so that the thickness of the tube decreases without
  limit and that the local field gradients increase rapidly with the
  passage of time until destroyed by one or more dissipative effects. The
  magnetic energy of a dislocated flux tube is therefore soon converted
  into thermal energy no matter how low the molecule resistivity of
  the fluid. Some formal illustrations of local conditions along a
  misaligned flux tube are presented, showing the simultaneous onset
  of diffusion, fluid motion, and hydromagnetic wave propagation. The
  examples demonstrate that the total effect is complicated and subject
  only to estimation, rather than formal calculation, at the present time.

Title: Residual fields from extinct dynamos
Authors: Parker, E. N.
Bibcode: 1981GApFD..18..175P
Altcode:
  The paper explores some of the many facets of the problem of the
  generation of magnetic fields in convective zones of declining vigor
  and/or thickness. The ultimate goal of such work is the explanation
  of the magnetic fields observed in A-stars. The present inquiry
  is restricted to kinematical dynamos, to show some of the many
  possibilities, depending on the assumed conditions of decline of the
  convection. The examples serve to illustrate in what quantitative
  detail it will be necessary to describe the convection in order to
  extract any firm conclusions concerning specific stars. The first
  illustrative example treats the basic problem of diffusion from a
  layer of declining thickness. The second adds a buoyant rise to the
  field in the layer. The third treats plane dynamo waves in a region
  with declining eddy diffusivity, dynamo coefficient, and large-scale
  shear. The dynamo number may increase or decrease with declining
  convection, with an increase expected if the large-scale shear does
  not decline as rapidly as the eddy diffusivity. It is shown that one
  of the components of the field may increase without bound even in the
  case that the dynamo number declines to zero.

Title: The spontaneous concentration of magnetic field in the
    photosphere of the sun.
Authors: Parker, E. N.
Bibcode: 1981ASIC...68...33P
Altcode: 1981spss.conf...33P
  The basic physics of magnetic flux tubes in the solar photosphere is
  reviewed, with areas still open to conjecture pointed out. The question
  of the concentration of individual small flux tubes to levels of 1-2
  kilogauss, when the average solar surface magnetic field is on the
  order of 10 gauss, by processes of twisting and the formation of flux
  ropes made up of tubes wound around each other is considered together
  with the effects of turbulence on the flux tube. Mechanisms for tube
  compression by the evacuation of the gas contained within a flux tube
  are then examined, and the possibility of field concentration through
  the cooling of the gas within the tube in a superadiabatic process is
  suggested. Attention is then given to possible mechanisms serving to
  maintain the concentration of flux tubes far below the surface of the
  sun which gives rise to sunspots and pores as the flux tree emerges
  through the surface.

Title: Summary Commentary - Solar Phenomena in Stars and Stellar
    Systems
Authors: Parker, E. N.
Bibcode: 1981ASIC...68..551P
Altcode: 1981spss.conf..551P
  No abstract at ADS

Title: A review of: "Solar flare magnetohydrodynamics"
Authors: Parker, E. N.
Bibcode: 1981GApFD..18..332P
Altcode:
  Edited by E. R. Priest (Volume 1 of "The Fluid Mechanics of Astrophysics
  and Geophysics"). Gordon and Breach Science Publishers, 1981. xii +
  563 pp. (Cloth Bound $89.50). (ISBN 0 677 0553 7 and ISSN 0 2604353).

Title: Solar System Plasma Physics.
Authors: Lanzerorotti, L. J.; Kennel, C. F.; Parker, E. N.
Bibcode: 1980JPlPh..24..191L
Altcode:
  No abstract at ADS

Title: Book-Review - Solar System Plasma Physics
Authors: Kennel, C. F.; Lanzerotti, L.; Parker, E. N.; Akasofu, S. I.
Bibcode: 1980Natur.285..598K
Altcode:
  No abstract at ADS

Title: Book-Review - Cosmical Magnetic Fields
Authors: Parker, E. N.; de Groot, M.
Bibcode: 1980IrAJ...14..189P
Altcode:
  No abstract at ADS

Title: Book-Review - Solar System Plasma Physics
Authors: Kennel, C. F.; Lanzerotti, L. J.; Parker, E. N.; Hultqvist, B.
Bibcode: 1980SSRv...26R.449K
Altcode:
  No abstract at ADS

Title: Sunspots and the physics of magnetic flux
    tubes. VIII. Overstability in a magnetic field in a downdraft.
Authors: Parker, E. N.
Bibcode: 1979ApJ...233.1005P
Altcode:
  The dynamical properties of convective overstability in a vertical
  magnetic field with a downdraft are considered. A variety of effects
  is illustrated. The overstability produces Alfven waves propagating
  both upward or downward along the magnetic field. The favored direction
  of emission may be upward or downward depending upon the magnitude of
  the heat transport coefficient. The largest asymmetry is produced by a
  difference in reflectivity between the upper and lower boundaries. It is
  shown that a very modest reflection coefficient of the upper boundary,
  with no reflection at the lower boundary, causes most of the waves
  to be emitted downward, and vice versa. Applying these results to
  the flux tubes extending up through the convective zone of the Sun,
  it follows that those flux tubes are dynamically active beneath the
  surface, as suggested earlier by ourselves and others, but there
  is no reason to expect any significant wave flux to appear in the
  field above the surface. The waves propagate downward into the Sun
  and are presumably dispersed there by the nonlinear interaction with
  the turbulent convection, etc.

Title: Sunspots and the physics of magnetic flux tubes. IX. Umbral
    dots and longitudinal overstability.
Authors: Parker, E. N.
Bibcode: 1979ApJ...234..333P
Altcode:
  The dynamical properties of the sunspot field and of a column of
  hot gas confined by such a vertical magnetic field are examined in
  order to understand the umbral dot within the context of the magnetic
  sunspot structure. Attention is given to the conditions necessary
  for gas intrusion, longitudinal as well as convective overstability,
  the growing modes, and the even mode. With the hypothesis that the
  subsurface magnetic field of a sunspot splits into many separate flux
  tubes with field-free gas between, it is suggested that the field-free
  columns occasionally punch their way up through the overlying magnetic
  field to the surface, appearing there as the bright, field-free umbral
  dots. Effects fostering the phenomenon are also discussed, that is, the
  enhanced temperature of a column of rising gas, the strongly reduced
  overhead magnetic pressure, and the initiated upward intrusion; these
  effects are illustrated with examples.

Title: Sunspots and the Physics of Magnetic Flux Tubes. VII. Heat
    Flow in a Convective Downdraft
Authors: Parker, E. N.
Bibcode: 1979ApJ...232..291P
Altcode:
  The heat flux in the familiar Boussinesq convective cell with free
  upper and lower boundaries is plotted to show the suppression of the
  upward heat flow by a downdraft. Application to the solar convective
  zone shows that downdrafts of 1-2 km 1 at depths of 1 x 1O km beneath
  the visible surface of the Sun are sufficient to reduce the upward heat
  flux to a small fraction of the ambient value. Hence the downdraft
  that is postulated to operate beneath the sunspot, to account for
  the gathering of flux tubes to form the spot, would be sufficient
  to reduce the heat flux to values comparable to those observed in
  sunspot umbrae. This greatly relieves the demands on cooling by the
  convective generation of Alfve'n waves in order to form the observed
  intense fields of 3000 gauss or more. Subject headings: convection -
  hydromagnetics - Sun: sunspots

Title: Sunspots and the physics of magnetic flux tubes. VI. Convective
    propulsion.
Authors: Parker, E. N.
Bibcode: 1979ApJ...232..282P
Altcode:
  The effect of negative aerodynamic drag in an ideal fluid subject to
  convective instability is considered. It is shown that a cylinder moving
  in such a fluid is propelled forward in its motion by the convective
  forces and that the characteristic acceleration time is comparable to
  the onset time of convective motions in the fluid. It is suggested that
  convective propulsion plays an important role in the dynamics of flux
  tubes extending through the surface of the sun. The suppression of the
  upward heat flow in a Boussinesq convective cell with free upper and
  lower boundaries by a downdraft is then analyzed. Application to the
  solar convection zone indicates that downdrafts of 1 to 2 km/s at depths
  of 1000 to 4000 km beneath the visible surface of the sun are sufficient
  to reduce the upward heat flux to a small fraction of the ambient value.

Title: Sunspots and the physics of magnetic flux tubes. V. Mutual
    hydrodynamic forces between neighboring tubes.
Authors: Parker, E. N.
Bibcode: 1979ApJ...231..270P
Altcode:
  The mutual hydrodynamic forces between parallel cylinders in a moving
  fluid are illustrated through several formal examples. Parallel tubes
  in a uniform flow are attracted or repelled depending on whether
  they are side by side or one ahead of the other, respectively. A
  pulsating or undulating tube attracts all other neighboring tubes toward
  itself. These hydrodynamic effects suggest that the separate flux tubes
  beneath the sunspots exert significant attractive forces on each other.

Title: Sunspots and the physics of magnetic flux
    tubes. III. Aerodynamic lift.
Authors: Parker, E. N.
Bibcode: 1979ApJ...231..250P
Altcode:
  The aerodynamic lift exerted on a magnetic flux tube by the asymmetric
  flow around the two sides of the tube is calculated as part of
  an investigation of the physics of solar flux tubes. The general
  hydrodynamic forces on a rigid circular cylinder in a nonuniform flow of
  an ideal fluid are derived from the first derivatives of the velocity
  field. Aerodynamic lift in a radial nonuniform flow is found to act
  in the direction of the flow, toward the region of increased flow
  velocity, while in a shear flow, lift is perpendicular to the free
  stream and directed toward increasing flow velocity. For a general,
  three dimensional, large-scale stationary incompressible equilibrium
  flow, an expression is also derived relating the lift per unit length
  to the dynamical pressure, cylinder radius and the gradient of the
  free-stream velocity. Evidence from an asymmetric airfoil in a uniform
  flow indicates that lift is enhanced in a real fluid in the presence
  of turbulence.

Title: Sunspots and the physics of magnetic flux
    tubes. II. Aerodynamic drag.
Authors: Parker, E. N.
Bibcode: 1979ApJ...230..914P
Altcode:
  No abstract at ADS

Title: Sunspots and the physics of magnetic flux tubes. I. The
    general nature of the sunspots.
Authors: Parker, E. N.
Bibcode: 1979ApJ...230..905P
Altcode:
  Analysis of the dynamical stability of a large flux tube suggests
  that the field of a sunspot must divide into many separate tubes
  within the first 1000 km below the surface. Buoyancy of the Wilson
  depression at the visible surface and probably also a downdraft beneath
  the sunspot hold the separate tubes in a loose cluster. Convective
  generation of Alfven waves, which are emitted preferentially downward,
  cools the tubes. Aerodynamic drag on a slender flux tube stretched
  vertically across a convective cell is also studied. Since the drag
  is approximately proportional to the local kinetic energy density,
  the density stratification weights the drag in favor of the upper
  layers. Horizontal motions concentrated in the bottom of the convective
  cell may reverse this density effect. A downdraft of about two km/sec
  through the flux tubes beneath the sunspot is hypothesized.

Title: The Instability of a Horizontal Magnetic Field in an Atmosphere
    Stable Against Convection
Authors: Parker, E. N.
Bibcode: 1979Ap&SS..62..135P
Altcode:
  The theoretical problem posed by the buoyant escape of a magnetic
  field from the interior of a stably stratified body bears directly on
  the question of the present existence of primordial magnetic fields in
  stars. This paper treats the onset of the Rayleigh-Taylor instability
  of the upper boundary of a uniform horizontal magnetic field in a
  stably stratified atmosphere. The calculations are carried out in
  the Boussinesq approximation and show the rapid growth of the initial
  infinitesimal perturbation of the boundary. This result is in contrast
  to the extremely slow buoyant rise of a separate flux tube in the
  same atmosphere. Thus for instance, at a depth of 1/3R <SUB>⊙</SUB>
  beneath the surface of the Sun, a field of 10<SUP>2</SUP> G develops
  ripples over a scale of 10<SUP>3</SUP> km in a characteristic time
  of 50 years, whereas the characteristic rise time of the same field
  in separate flux tubes with the same dimensions is 10<SUP>10</SUP>
  years. Thus, the development of irregularities proceeds quickly,
  soon slowing, however, to a very slow pace when the amplitude of the
  irregularities becomes significant. Altogether the calculations show
  the complexity of the question of the existence of remnant primordial
  magnetic fields in stellar interiors.

Title: INVITED PAPER - George Ellery Hale and Active Mangetic Fields
Authors: Parker, E. N.
Bibcode: 1979BAAS...11..423P
Altcode:
  No abstract at ADS

Title: Cosmical magnetic fields. Their origin and their activity
Authors: Parker, E. N.
Bibcode: 1979cmft.book.....P
Altcode:
  The physics of large-scale magnetic fields in fluids of high electrical
  conductivity is examined, with emphasis on the generation of magnetic
  fields in astronomical bodies and interactions of the fields with
  those bodies. The role and nature of cosmic magnetic fields are
  described and solutions to the basic electromagnetic equations are
  developed. Consideration is given to magnetic field stress and
  energy and the problem of magnetic equilibrium. The propagation
  of disturbances in a magnetic fluid is discussed, and the basic
  properties and interactions of isolated flux tubes and twisted flux
  tubes are considered. The topology of magnetic lines of force, the
  nonequilibrium of invariant and non-invariant fields, the breakup
  and escape of submerged magnetic fields, the rapid reconnection of
  magnetic lines of force, the exclusion of magnetic fields from closed
  circulation patterns, and the generation and nature of magnetic fields
  in turbulent fluids, including the dynamo problem, are treated, and
  planetary, solar, stellar and galactic magnetic fields are examined.

Title: Gearing up to answer question posed by the sun.
Authors: Parker, E. N.
Bibcode: 1979PhT....32i...9P
Altcode:
  No abstract at ADS

Title: The University of Chicago: Department of Astronomy and
    Astrophysics, Chicago, Illinois 60637; The Yerkes Observatory,
    Williams Bay, Wisconsin 53191. Report.
Authors: Parker, E. N.; Hobbs, L. M.
Bibcode: 1979BAAS...11...80P
Altcode:
  No abstract at ADS

Title: The enigma of solar activity.
Authors: Parker, E. N.
Bibcode: 1979psa..conf....8P
Altcode:
  No abstract at ADS

Title: Book-Review - Cosmical Magnetic Fields - Their Origin and
    Their Activity
Authors: Parker, E. N.
Bibcode: 1979AstQ....3..201P
Altcode:
  No abstract at ADS

Title: Solar system plasma physics. Vol.1: Solar and solar wind plasma
physics; Vol.2: Magnetospheres; Vol.3: Solar system plasma processes
Authors: Parker, E. N.; Kennel, Charles F.; Lanzerotti, Louis J.
Bibcode: 1979sspp.book.....P
Altcode:
  No abstract at ADS

Title: Summary Remarks
Authors: Parker, E. N.
Bibcode: 1979AIPC...56..425P
Altcode: 1979pama.work..425P
  No abstract at ADS

Title: Solar system plasma physics. Volume 3 - Solar system plasma
    processes
Authors: Lanzerotti, L. J.; Kennel, C. F.; Parker, E. N.
Bibcode: 1979anh..book.....L
Altcode:
  The papers deal with such solar system plasma processes as shocks
  in collisionless space plasmas; magnetic field reconnection,
  hydrodynamic waves; plasma processes in the earth's radiation belts;
  and magnetospheric plasma waves. Some papers deal with the ionospheric
  plasma; the physics of heavy ions in the magnetosphere; impacts
  of ionospheric-magnetospheric processes on terrestrial science and
  technology; and impacts of the solar system environment on man, and
  vice versa.

Title: Solar system plasma physics. Volume 1 - Solar and solar wind
    plasma physics
Authors: Parker, E. N.; Kennel, C. F.; Lanzerotti, L. J.
Bibcode: 1979sswp.book.....P
Altcode:
  The paper covers such aspects of solar physics as the mechanisms which
  drive solar phenomena (such as heating of the corona, the acceleration
  of particles in flares, the dissipation of magnetic energy in current
  sheets, and the generation of the solar wind), the structure and
  energetics of the quiet solar atmosphere, the structure of the corona,
  the solar composition, and solar terrestrial interactions. Phenomena
  associated with solar flares are discussed, and physical mechanism which
  have been advanced to explain them are examined. The impact of solar
  physics on the development of plasma physics and magnetohydrodynamics
  is noted. The mathematical framework describing the microscopic and
  macroscopic aspects of the solar wind plasma is outlined

Title: A broad look at solar physics adapted from the solar physics
    study of August 1975
Authors: Parker, E.; Timothy, A.; Beckers, J.; Hundhausen, A.; Kundu,
   M. R.; Leith, C. E.; Lin, R.; Linsky, J.; MacDonald, F. B.; Noyes, R.
Bibcode: 1979sswp.book....3P
Altcode: 1979sswp.book....3B
  The current status of our knowledge of the basic mechanisms involved
  in fundamental solar phenomena is reviewed. These include mechanisms
  responsible for heating the corona, the generation of the solar
  wind, the particle acceleration in flares, and the dissipation of
  magnetic energy in field reversal regions, known as current sheets. The
  discussion covers solar flares and high-energy phenomena, solar active
  regions; solar interior, convection, and activity; the structure and
  energetics of the quiet solar atmosphere; the structure of the corona;
  the solar composition; and solar terrestrial interactions. It also
  covers a program of solar research, including the special observational
  requirements for spectral and angular resolution, sensitivity, time
  resolution, and duration of the techniques employed.

Title: Solar system plasma physics. Volume 2 - Magnetospheres
Authors: Kennel, C. F.; Lanzerotti, L. J.; Parker, E. N.
Bibcode: 1979magn.book.....K
Altcode:
  The present volume covers such topics as global problems in
  magnetospheric plasma physics; magnetosphere, ionosphere, and
  atmosphere interactions; Jupiter's magnetosphere and radiation belts,
  the magnetosphere of Mercury; interactions of the solar wind with
  the planets Mars, Venus, and Mercury; and interactions between the
  solar wind and comets. The theory of planetary dynamics is outlined,
  and the contemporary basis for the development of a comparative theory
  of magnetospheres is examined.

Title: The mutual attraction of magnetic knots.
Authors: Parker, E. N.
Bibcode: 1978ApJ...222..357P
Altcode:
  It is observed that the magnetic knots associated with active regions
  on the sun have an attraction for each other during the formative
  period of the active regions, when new magnetic flux is coming to
  the surface. The attraction disappears when new flux ceases to rise
  through the surface. Then the magnetic spots and knots tend to come
  apart, leading to disintegration of the sunspots previously formed. The
  dissolution of the fields is to be expected, as a consequence of the
  magnetic repulsion of knots of like polarity and as a consequence of
  the hydromagnetic exchange instability. The purpose of this paper is to
  show that the mutual attraction of knots during the formative stages
  of a sunspot region may be understood as the mutual hydrodynamic
  attraction of the rising flux tubes. Two rising tubes attract each
  other, as a consequence of the wake of the leading tube when one is
  moving behind the other, and as a consequence of the Bernoulli effect
  when rising side by side.

Title: Hydraulic concentration of magnetic fields in the solar
    photosphere. VI. Adiabatic cooling and concentration in downdrafts.
Authors: Parker, E. N.
Bibcode: 1978ApJ...221..368P
Altcode:
  The remarkable concentration of the general field of the Sun into
  isolated intense flux tubes at the visible surface must be a direct
  consequence of conditions immediately beneath the surface. It is pointed
  out that the convective heat transport in the magnetic field swept into
  the downdrafts in the junctions of supergranule boundaries is strongly
  suppressed by the magnetic field. The net heat transport is reduced to
  such a degree that the temperature of the downdraft within the field
  increases nearly adiabatically below the visible surface, and hence
  is significantly cooler than the surrounding ambient gas. The reduced
  temperature enhances the downdraft within the field and permits the
  gravitational field to evacuate the flux tube. The magnetic field is
  then strongly compressed by the external gas pressure, leading to the
  extraordinary observed strengths of 1500 gauss or more. It is suggested
  that the magnetic knots found in active regions are formed wholly or
  partly by the same effect. The general occurrence of superadiabatic
  temperature gradients and convective heat transport in the dwarf and
  subdwarf main-sequence stars suggests that their magnetic fields are
  generally broken up and concentrated by this effect, much as in the
  Sun. Subject headings: convection hydromagnetics - Sun: granulation -
  Sun: magnetic fields

Title: The University of Chicago, Department of Astronomy and
    Astrophysics, Chicago, Illinois; The Yerkes Observatory, Williams Bay,
    Wisconsin. Reports.
Authors: Parker, E. N.; Hobbs, L. M.
Bibcode: 1978BAAS...10Q..77P
Altcode:
  No abstract at ADS

Title: The University of Chicago, Department of Astronomy and
    Astrophysics, Chicago, Illinois. The Yerkes Observatory, Williams Bay,
    Wisconsin. Reports.
Authors: Parker, E. N.; Hobbs, L. M.
Bibcode: 1978BAAS...10R..77P
Altcode:
  No abstract at ADS

Title: Solar Physics in Broad Perspective
Authors: Parker, E. N.
Bibcode: 1978nsp..conf....1P
Altcode:
  No abstract at ADS

Title: The relative diffusion of strong magnetic fields and tenuous
    gases.
Authors: Parker, E. N.
Bibcode: 1977ApJ...215..374P
Altcode:
  General equations are given for treating the diffusion of a magnetic
  field in a fluid with electrical conductivity and a resistive diffusion
  coefficient. Consequences of nonnegligible gas motion are investigated
  by considering the one-dimensional problem where a tenuous isothermal
  gas with pressure expressed as a function of x-coordinate and time is
  enmeshed in a magnetic field in the y-direction. Approximate equations
  are obtained for the case of weak fluctuations in gas or field
  pressure, and the properties of a nonlinear diffusion equation are
  illustrated with the example of an initial thin slab of gas confined
  by a uniform field on either side. The advance of a gas front into a
  nonvanishing gas density is illustrated by using the progressive wave
  solution. Application of the results to the evolution of streamers
  and filaments observed in the solar corona is briefly discussed

Title: The generation of magnetic fields in astrophysical
    bodies. XI. The effect of magnetic buoyancy on the growth and
    migration of dynamo waves in the sun.
Authors: Parker, E. N.
Bibcode: 1977ApJ...215..370P
Altcode:
  The hydromagnetic dynamo equations are solved including a simple
  magnetic buoyancy term to demonstrate the effect of the buoyant
  rise of the magnetic field on the operation of the solar dynamo. The
  calculations show that the strength of the fluid motions necessary
  for the generation of field is sharply increased in a dynamo driven
  principally by vertical shear, as a consequence of the rapid, buoyant
  loss of field out of the free upper surface. In a dynamo driven by
  horizontal shear, such as the observed nonuniform rotation of the
  Sun, the necessary fluid motions are stronger or weaker depending
  upon whether the vertical migration of the dynamo waves is upward or
  downward, respectively. Unfortunately, our present ignorance of the
  fluid motions in the Sun excludes any more detailed conclusion than the
  general remark that the buoyancy has important quantitative effects on
  the operation of the solar dynamo. Subject headings: hydromagnetics -
  Sun: magnetic fields

Title: A comment on the thermal structure of sunspots
Authors: Parker, E. N.
Bibcode: 1977MNRAS.179P..93P
Altcode:
  Summary. It is pointed out that, at the present time, there is no
  certain explanation for the spontaneous self-concentration of magnetic
  fields to form the cool sunspots on the surface of the Sun. A brief
  discussion is presented, with comments on a recent paper by Cowling.

Title: Comment on "the Elementary Theory of Twisted Flux
    Tubes. Equilibrium Configurations
Authors: Parker, E. N.
Bibcode: 1977ApJ...214..616P
Altcode:
  It is pointed out that Wilson's calculations confirm the validity of our
  earlier results on the variation of fields along a slender force-free
  magnetic flux tube with slowly varying radius R(z) ( R/ z 1). The
  field distributions across tube are correct, neglecting terms O( R/ z)
  compared to one. Subject headings: hydromagnetics - Sun: magnetic fields

Title: Cosmic-ray propagation and containment.
Authors: Parker, E. N.
Bibcode: 1977NASCP...2..283P
Altcode: 1977scgr.nasa..283P; 1977NASCP.002..283P
  The cosmic rays are an active gaseous component of the disk of
  the galaxy, and their propagation and containment is a part of the
  general dynamics of the disk. The sources of cosmic rays are a matter
  of speculation. The disk is inflated by the cosmic-ray gas pressure,
  P, comparable to the magnetic pressure B super 2/ 8 pi, but the rate
  of inflation is unknown. The time spent by the individual cosmic-ray
  particles in the disk is inversely proportional to the cosmic-ray
  production rate and may be anything from 100,000 to more than 10 million
  years. It is evident from the decay of Be(10) that the cosmic rays
  circulate through a volume of space perhaps ten times the thickness of
  the gaseous disk, suggesting a magnetic halo extending out approximately
  1 kpc from either face of the disk. The cosmic rays may be responsible
  for the halo by inflating the magnetic fields of the disk. Extension
  of the fields to 1 kpc would imply a high production rate and short
  life of cosmic rays in the dense gaseous disk of the galaxy.

Title: The University of Chicago, Department of Astronomy and
    Astrophysics, Chicago, Illinois; The Yerkes Observatory, Williams Bay,
    Wisconsin. Observatory reports.
Authors: Parker, E. N.; Hobbs, L. M.
Bibcode: 1977BAAS....9...73P
Altcode:
  No abstract at ADS

Title: The origin of solar activity.
Authors: Parker, E. N.
Bibcode: 1977ARA&A..15...45P
Altcode:
  The basis physical problems and principles of solar activity are
  reviewed, insofar as they are understood, concentrating on the general
  question of why magnetic fields produce activity. The continuous
  emergence of magnetic flux tubes through the solar surface is examined,
  the origin of solar magnetic fields is considered, and the behavior
  of the magnetic fields is investigated. Magnetic buoyancy is analyzed
  together with flux-tube twisting, the variation of twisting along
  a flux tube, magnetic-field concentration into isolated flux tubes,
  and dynamical dissipation of magnetic fields. It is concluded that the
  fluid motions which produce the magnetic fields in the convecting sun
  generally prevent the fields from achieving the perfect topological
  symmetry necessary for the existence of an equilibrium, that these
  fields should be active (i.e., perpetually in a state of reconnection),
  and that this seems to be the cause of the continuous activity of the
  magnetic fields which emerge through the surface of the sun.

Title: Hydraulic concentration of fields in the solar
    photosphere. IV. Evolution of fields near equipartition.
Authors: Parker, E. N.
Bibcode: 1976ApJ...210..810P
Altcode:
  It has previously been inferred that small isolated flux tubes appearing
  in supergranule boundaries are compressed to 1500 gauss or more. This
  paper considers whether some dynamic condition within a flux tube
  exists which provides both stability and a 'mechanical advantage'
  so that a small force over a small period of time can accomplish the
  enormous compression from the weak-field to the strong-field state. It
  is found that the equipartition solutions to the hydromagnetic
  equations apparently may have the desired property of permitting
  an infinitesimal external pressure to convert a gentle flow of gas
  along a weak field into a very intense field through a succession of
  equipartition states. An illustrative example is presented, and field
  compression by convective forces is analyzed.

Title: Hydraulic Concentration of Fields in the Solar
    Photosphere. V. Dynamical Effects in a Stratified Atmosphere
Authors: Parker, E. N.
Bibcode: 1976ApJ...210..816P
Altcode:
  The dynamical equations are presented for the steady flow of an inviscid
  ideal gas along a magnetic tube of force extending vertically across a
  stratified atmosphere with temperature T(z) in a uniform gravitational
  acceleration g. It is shown that under usual conditions an equilibrium
  dynamical solution extends across the full height of the atmosphere
  only if there is a point somewhere in the atmosphere where d(kT/mg)/dz
  = . If such a critical point exists, then the dynamical solutions
  extend across the atmosphere and possess the property of strong
  concentration of field in the general neighborhood of the critical
  point, where the fluid and field cross over equipartition, pV2 =
  B2/8ir. It is shown that the necessary condition on the temperature
  gradient is satisfied in the Sun in the top 50 km of the convective
  zone, suggesting that the observed concentration of magnetic field
  to 10 gauss or more in the photosphere is a localized phenomenon
  attributable at least in part to the dynamical flow of gas along the
  field. A crucial observational test for the occurrence of dynamical
  concentration would be a determination of the gas velocity ( j 5 km s
  -1) in the region of concentration. Subject headings: hydromagnetics -
  Sun: atmosphere - Sun: magnetic fields

Title: Basic Properties of Magnetic Flux Tubes and Restrictions on
    Theories of Solar Activity
Authors: Parker, E. N.
Bibcode: 1976Ap&SS..44..107P
Altcode:
  It is shown that the mean longitudinal field in a magnetic flux tube
  is reduced, rather than enhanced, by twisting the tube to form a
  rope. It is shown that there is no magnetohydrostatic equilibrium
  when one twisted rope is wound around another. Instead there is
  rapid line cutting (neutral point annihilation). It is shown that the
  twisting increases, and the field strength decreases, along a flux
  tube extending upward through a stratified atmosphere. These facts are
  at variance with Piddington's recent suggestion that solar activity
  is to be understood as the result of flux tubes which are enormously
  concentrated by twisting, which consist of several twisted ropes wound
  around each other, and which came untwisted where they emerge through
  the photosphere.

Title: On the physical interpretation of the cosmic-ray transport
    equations.
Authors: Jokipii, J. R.; Parker, E. N.
Bibcode: 1976ApJ...208..220J
Altcode:
  It is pointed out that an earlier paper (Jokipii and Parker, 1967)
  had discussed in detail the question of the interpretation of the
  energy-change terms in the general equation for cosmic-ray transport
  in the solar wind, so that no need exists to reassess the physical
  interpretation, as urged by Gleeson and Webb (1974). The question
  concerns the expression for the adiabatic deceleration, which is
  'replaced' by an expression for the mean rate of change of momentum of
  fast particles. It is pointed out that these two expressions represent
  two essentially different quantities. The adiabatic deceleration refers
  to the mean rate loss of kinetic energy of an individual particle
  as a result of the expansion of the gas and magnetic field of the
  wind. This parameter can in no way depend on the gradient of the fast
  particle density, as does the mean rate of change of momentum of the
  fast particles.

Title: Astronomers' Petition
Authors: Schramm, David N.; Anders, Edward; Chandrasekhar, S.; Palmer,
   Patrick; Parker, Eugene; Simpson, J. A.
Bibcode: 1976Sci...191.1124S
Altcode:
  No abstract at ADS

Title: Hydraulic concentration of magnetic fields in the solar
    photosphere. III. Fields of one or two kilogauss.
Authors: Parker, E. N.
Bibcode: 1976ApJ...204..259P
Altcode:
  Detailed analysis of weak and strong lines suggests that the magnetic
  fields in isolated intense flux tubes in supergranule boundaries in
  the solar photosphere may be as large as 2000 gauss. This paper is a
  concise systematic review of hydrodynamic effects that might compress a
  magnetic field to great intensity. The properties of force-free fields
  are reviewed to show that they do not contribute to concentration of
  magnetic fields, in spite of the popular notion to the contrary. Of
  the seven effects considered, it is concluded that only cooling of the
  gas within the field can produce the high field densities inferred
  from observation. It is shown that inhibition of convection appears
  not to possess the necessary qualitative cooling features and that
  overstability, generating transverse hydromagnetic waves - essentially
  Alfven waves - is the only way to account for the cooling and field
  intensification.

Title: The Enigma of Solar Activity
Authors: Parker, E. N.
Bibcode: 1976IAUS...71....3P
Altcode:
  No abstract at ADS

Title: The Acceleration of Particles to High Energy
Authors: Parker, E. N.
Bibcode: 1976ASIC...28..137P
Altcode: 1976pntr.conf..137P
  No abstract at ADS

Title: The Basic Physical Properties of a Galactic Magnetic Field
Authors: Parker, E. N.
Bibcode: 1976ASIC...28..169P
Altcode: 1976pntr.conf..169P
  No abstract at ADS

Title: University of Chicago, Department of Astronomy and
    Astrophysics, Chicago, Illinois; The Yerkes Observatory, Williams Bay,
    Wisconsin. Observatory reports.
Authors: Parker, E. N.; Hobbs, L. M.
Bibcode: 1976BAAS....8...54P
Altcode:
  No abstract at ADS

Title: The magnetic fields of planets
Authors: Parker, E. N.
Bibcode: 1976pspe.proc..812P
Altcode:
  The magnetic fields of planets are considered, taking into account
  the history of the geomagnetic field characteristics, the magnetic
  field of Jupiter, the magnetic properties of Mars, the significance
  of a failure to detect signs of a magnetic field during the passage
  of Mariner 10 near Venus, the discovery of a magnetic field during
  the passage of Mercury, the absence of a lunar magnetic field, and
  the magnetic field of the sun. The causes of planetary magnetism are
  discussed and attention is given to dynamic considerations.

Title: The escape of magnetic flux from a turbulent body of gas.
Authors: Parker, E. N.
Bibcode: 1975ApJ...202..523P
Altcode:
  Topological conditions on the surface of a turbulent body of highly
  conductive fluid under which escape of magnetic force lines would
  be impossible (Drobyshevski, Yuferev 1974) are studied with exact
  calculation of intermediate field configurations as a possible
  explanation of the decay of stellar magnetic fields via turbulent
  mixing. It is shown that upward escape of magnetic force lines in the
  regions between convective cells is possible through rapid reconnection
  of the force lines (studied as neutral point annihilation) such as
  occurs continually in rapidly evolving sunspot groups. It is concluded
  that there exists no topological barrier to the escape of magnetic
  flux from the sun or from the local galaxy.

Title: X-ray bright spots on the sun and the nonequilibrium of a
    twisted flux rope in a stratified atmosphere.
Authors: Parker, E. N.
Bibcode: 1975ApJ...201..494P
Altcode:
  The calculations are concerned with the hydrostatic equilibrium of
  a magnetic flux tube whose two ends are anchored at some level in a
  stratified atmosphere. It is shown that no hydrostatic equilibrium
  exists if the whole flux tube is twisted more than a modest amount,
  equivalent to a 450 pitch over only one scale height. When the total
  twisting exceeds this small amount, the tube is subject to negative
  tension (compression) and buckles, spirals, and/or lengthens into
  a contorted form which causes rapid dissipation and reconnection of
  the magnetic field. The rapid dissipation continues until the excess
  azimuthal field is consumed and equilibrium is again possible. We
  suggest that the magnetic flux tubes in the Sun generally have more
  than the allowed twisting, so that, when they rise up through the
  surface, as a consequence of their buoyancy, they are subject to
  rapid dissipation, causing the phenomenon observed as the X-ray bright
  spot. Subject headings: hydromagnetics - Sun - X-rays, solar

Title: Solar activity and the general absence of hydrostatic
    equilibrium in an azimuthal magnetic field.
Authors: Parker, E. N.
Bibcode: 1975ApJ...201..502P
Altcode:
  It is shown that any temperature variation along the axis of symmetry
  of an azimuthal field causes continual convective activity. There is
  no static equilibrium configuration except in very special, and hence
  improbable, cases. It is suggested that this dynamic effect contributes
  to the activity associated with the flux tubes extending through the
  solar photosphere. The X-ray bright spots, evidently caused by the
  emergence and expansion of small bipolar regions, may be produced in
  part by the convective effect of an azimuthal field.

Title: Comment on "The stabilizing effects of cloud reacceleration,
    microturbulence, and rotation on Parker's instability".
Authors: Parker, E. N.
Bibcode: 1975ApJ...201...74P
Altcode:
  It is pointed out that the calculations in the paper by Zweibel and
  Kulsrud do not speak to the question of the instability and evolution of
  the gaseous disk of the Galaxy. Rather, they seem to treat the question
  of the statistical stability of the present turbulent dynamical
  state. Subject headings: hydromagnetics - interstellar matter -
  turbulence

Title: The sun.
Authors: Parker, E. N.
Bibcode: 1975SciAm.233c..42P
Altcode: 1975SciAm.233...42P
  The development of scientific knowledge of the sun is reviewed from
  Emden's first theoretical solar model (early 19th century) to the
  latest Skylab observations. Concepts dealt with include the solar
  wind, solar activity, energetic processes, thermonuclear generation
  of energy, and solar neutrinos. The carbon-nitrogen cycle and the
  proton-proton chain are outlined, and attempts at neutrino detection
  are discussed. Magnetohydrodynamic activity on the sun is described
  together with the nature and behavior of sunspots. Possible effects
  of sunspot activity on terrestrial weather are considered.

Title: The Dynamo Mechanism for the Generation of Large-Scale
    Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1975NYASA.257..141P
Altcode:
  No abstract at ADS

Title: The generation of magnetic fields in astrophysical
    bodies. X. Magnetic buoyancy and the solar dynamo.
Authors: Parker, E. N.
Bibcode: 1975ApJ...198..205P
Altcode:
  The magnetic field appearing as bipolar magnetic regions at the surface
  of the sun represents the lines of force from a general azimuthal
  field of the order of 100 gauss somewhere beneath the surface. The
  amplification time, as a consequence of the nonuniform rotation, is
  of the order of 10 years. But magnetic buoyancy brings the azimuthal
  field up through much of the convective zone in a time rather less
  than 10 years, raising the question of where the azimuthal field can
  be retained long enough to be amplified. We show that magnetic fields
  can be retained for long periods of time in the stable radiative region
  beneath the convective zone, but unfortunately the solar dynamo cannot
  function there because turbulent diffusion is an essential part of its
  operation. The only possible conclusion appears to be that the dynamo
  operates principally in the very lowest levels of the convective zone
  at depths of 150,000 km or more, where the gas density is 0.1 g/cu cm,
  and the fields are limited to 50 gauss.

Title: The Nature of the Sunspot Phenomenon. IV: The Intrinsic
    Instability of the Magnetic Configuration
Authors: Parker, E. N.
Bibcode: 1975SoPh...40..291P
Altcode:
  It is pointed out that the equilibrium configuration of a sunspot
  magnetic field, confined to the cool umbra by the pressure of the
  surrounding photospheric gas, is unstable to the familiar hydromagnetic
  exchange instability. The characteristic time for dissolution of the
  sunspot is of the order of one hour.

Title: The Nature of the Sunspot Phenomenon. III: Energy Consumption
    and Energy Transport
Authors: Parker, E. N.
Bibcode: 1975SoPh...40..275P
Altcode:
  This paper points out the basic relation between the conversion of
  thermal energy into convective fluid motion (Alfvén waves when a strong
  vertical magnetic field is present) and the convective transport of
  thermal energy. It is shown that heat transport necessarily accompanies
  convective driving of fluid motion. Convective motions restricted to
  a layer whose thickness is a small fraction of the local scale height
  can divert no more than the same fraction of the energy into Alfvén
  waves. But if the convecting layer extends over many scale heights,
  then the convective forces may convert more energy into fluid motion
  than they transport. Hence the creation of a cool sunspot requires
  convection extending coherently over several scale heights, at least
  500 km. This requirement is basically just the familiar thermodynamic
  efficiency of an ideal heat engine. The calculations establish that
  convection need not be much less efficient than the ideal.

Title: Book Review: Cosmic gas dynamics. EVRY SCHATZMAN and LUDWIG
BIERMANN: John Wiley, New York, 1974. xv + 291 pp. £8.40
Authors: Parker, E. N.
Bibcode: 1975P&SS...23..388P
Altcode:
  No abstract at ADS

Title: The dynamo mechanism for the generation of large-scale
    magnetic fields.
Authors: Parker, E. N.
Bibcode: 1975NYASA.257Q.141P
Altcode:
  No abstract at ADS

Title: The University of Chicago, Department of Astronomy and
    Astrophysics, Chicago, Illinois; The Yerkes Observatory, Williams Bay,
    Wisconsin. Observatory reports.
Authors: Parker, E. N.; Hobbs, L. M.
Bibcode: 1975BAAS....7...25P
Altcode:
  No abstract at ADS

Title: The dynamo mechanism for the generation of larg-scale magnetic
    fields.
Authors: Parker, E. N.
Bibcode: 1975NYASA.257R.141P
Altcode:
  No abstract at ADS

Title: The Instability of Strong Magnetic Fields in Stellar Interiors
Authors: Parker, E. N.
Bibcode: 1974Ap&SS..31..261P
Altcode:
  There has been discussion of the possibility of resolving the
  solar neutrino dilemma with a sufficiently strong magnetic field
  (5×10<SUP>8</SUP> G) in the solar interior to relieve the gas pressure
  by some ten percent or more. We examine the time in which magnetic
  buoyancy will bring a strong field to the surface and find it to be
  less than 10<SUP>8</SUP> yr. We see no possibility for retaining a
  suitably strong magnetic field in the solar interior.

Title: The Nature of the Sunspot Phenomenon. II: Internal Overstable
    Modes
Authors: Parker, E. N.
Bibcode: 1974SoPh...37..127P
Altcode:
  The properties of Alfvén waves in a vertical column of field
  are pointed out as a guide in treating the complicated problem of
  overstability. There are internal Alfvén waves of arbitrary form
  propagating along the magnetic field, without disturbing the fluid
  outside the column. There are also surface waves which involve the
  fluid both inside and outside the column of field. The surface waves
  propagate at a speed less than the Alfvén speed.

Title: The Dynamical Properties of Twisted Ropes of Magnetic Field
    and the Vigor of New Active Regions on the Sun
Authors: Parker, E. N.
Bibcode: 1974ApJ...191..245P
Altcode:
  The equilibrium configuration following expansion of all, or part,
  of a force-free magnetic rope is worked out formally from the
  hydromagnetic equilibrium equations. It is shown that expansion of a
  portion of the length of a long magnetic rope beyond a certain radius
  causes the expanded portion to be wrapped with an azimuthal field
  composed of lines of force from the surface layer of the unexpanded
  portion. This singular redistribution takes an extended period of time
  to achieve. Further, it automatically causes the expanded portion to
  become unstable to buckling. We suggest that the restless behavior of
  the magnetic fields in new active regions in the solar photosphere is
  largely a result (a) of the buckling brought about by the expansion
  of the fields as they emerge through the photosphere, and (b) of the
  long-term redistribution of the surface lines of force onto the expanded
  portion of the rope. Subject headings: hydromagnetics - magnetic fields,
  solar - solar activity

Title: Hydraulic Concentration of Magnetic Fields in the Solar
    Photosphere. II. Bernoulli Effect
Authors: Parker, E. N.
Bibcode: 1974ApJ...190..429P
Altcode:
  The magnetic filaments in the solar photosphere are subject to vigorous
  kneading and massaging by the convective turbulence at, and beneath,
  the visible surface. It is shown that the Bernoulli effect of the
  consequent surging of fluid up and down along the filaments is a
  major factor in concentrating the magnetic pressure of the filament
  (the mean square field). The mean field is also increased if the phase
  velocity of the external massaging exceeds the Alfven speed within the
  filament. The net observational magnetic result of the surging, then,
  depends upon the response of the observing instrument, and whether
  it essentially observes the mean field, the rms field, or whether
  there are saturation effects. The hydraulic effects responsible for
  the formation of the concentrated magnetic filaments are part of the
  dynamical picture of spicules, pointed out a decade ago. Hence we
  suggest that the chromospheric mottles (spicules) seen in Ha are in
  fact the intense magnetic filaments that carry most of the magnetic flux
  across the photospheric boundary of the Sun. Subject headings: granules
  and supergranules, solar - hydromagnetics - magnetic fields, solar

Title: The Nature of the Sunspot Phenomenon. I: Solutions of the
    Heat Transport Equation
Authors: Parker, E. N.
Bibcode: 1974SoPh...36..249P
Altcode:
  Heat transport in the Sun is describable by a Fokker-Planck, or
  diffusion, transfer equation. A study of the general character of
  the solutions of the transfer equation shows that the inhibition of
  convective transport beneath the photosphere produces a photospheric
  dark ring surrounded by a bright ring, or at best, a dark area
  surrounded by a bright ring. The mean temperature beneath the `sunspot'
  is unavoidably above normal, so that the enhanced gas pressure would
  disperse, rather than concentrate, the magnetic field. Hence we conclude
  that the inhibition of convection cannot be the cause of a sunspot.

Title: Hydraulic Concentration of Magnetic Fields in the Solar
    Photosphere. I. Turbulent Pumping
Authors: Parker, E. N.
Bibcode: 1974ApJ...189..563P
Altcode:
  Observations suggest that most of the magnetic flux through the solar
  photosphere is concentrated in vertical filaments in the supergranule
  boundaries. Each filament appears to contain about 3 x 10' maxwells,
  in the form of a field of 500 gauss or more, over a diameter of 700 km
  or less. The magnetic energy density in the filaments is 100 times the
  observed kinetic energy density of the observed supergranule motions,
  but comparable to the kinetic energy density of the granules. Force-free
  field configurations cannot duplicate the observational numbers, nor
  can such cooling effects as are believed responsible for the intense
  fields in sunspot umbrae. We point out a simple hydraulic mechanism-
  turbulent pumping that appears to account for the observed concentration
  of fields. The mechanism is treated by using the simple mixing-length
  theory of convection and turbulence. Subject headings: atmospheres,
  solar - granules and supergranules, solar hydromagnetics - turbulence

Title: The University of Chicago: Department of Astronomy and
    Astrophysics, Chicago, Illinois; The Yerkes Observatory, Williams Bay,
    Wisconsin 1972-1973. Observatory reports.
Authors: Parker, E. N.; van Altena, W. F.
Bibcode: 1974BAAS....6R..15P
Altcode:
  No abstract at ADS

Title: The University of Chicago, Department of Astronomy and
    Astrophysics, Chicago, Illinois; The Yerkes Observatory, Williams Bay,
    Wisconsin 1972-1973. Observatory reports.
Authors: Parker, E. N.; van Altena, W. F.
Bibcode: 1974BAAS....6Q..15P
Altcode:
  No abstract at ADS

Title: Comment on "galactic Magnetic Fields: Cellular or Filamentary
    STRUCTURE?"
Authors: Parker, E. N.
Bibcode: 1974ApJ...187..191P
Altcode:
  The recent statistical studies of Michel and Yahil emphasize again the
  difficulty in interpreting the observed Faraday rotation measure in
  terms of an unambiguous model of the galactic magnetic field. We have
  difficulty in understanding their specific suggestion that the magnetic
  fields expelled from stars have anything to do with the model. Subject
  headings: interstellar matter magnetic fields - solar wind

Title: Convection and Magnetic Fields in an Atmosphere with Constant
    Temperature Gradient. II. The Supergranules and Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1973ApJ...186..665P
Altcode:
  The hydrodynamic properties of convective motions in a stratified
  atmosphere suggest that e supergranules in the solar photosphere extend
  to depths in excess of their horizontal diameters. The calculations
  presented here show that the weak fields which appear at the photosphere
  are as strong as, or stronger than, the horizontal fields anywhere in
  the supergranules below the surface. Hence the general gauss azimuthal
  field of the Sun, whose presence is indicated by the emerging bipolar
  magnetic regions, must lie below the base of the supergranules, i.e.,
  below a depth probably of the order of 2-5 x i0 km. Presumably then
  the azimuthal field is generated by nonuniform rotation below the
  supergranule convection and does not appear in the supergranule
  layer because of the high rate of turbulent diffusion loss from
  that layer. Subject headings: atmospheres, solar - granules, solar -
  hydromagnetics

Title: Convection and Magnetic Fields in an Atmosphere with Constant
    Temperature Gradient. I. Hydrodynamic Flows
Authors: Parker, E. N.
Bibcode: 1973ApJ...186..643P
Altcode:
  In order to deduce the fluid and field conditions deep in the
  supergranules from the fluid motions and magnetic fields observed
  in the solar photosphere, it is necessary to have some idea of the
  depth to which the supergranules extend and the form of their internal
  fluid velocities. Toward this end a number of analytic solutions of
  the Navier-Stokes equations are given for circumstances possessing
  various facets of the supergranule environment in the Sun. These
  solutions, together with the earlier work by others, shows that the
  granules extend to depths in excess of their mean diameters, that the
  convective velocities probably do not diminish much, if any, with depth,
  and that across the tops of the supergranules at the photosphere the
  horizontal velocity is more or less independent of depth. Subject
  headings: atmospheres, solar - granules, solar - hydrodynamics

Title: Extragalactic Cosmic Rays and the Galactic Magnetic Field
Authors: Parker, E. N.
Bibcode: 1973Ap&SS..24..279P
Altcode:
  The origin and behavior of cosmic rays in the Galaxy depends crucially
  upon whether the galactic magnetic field has a closed topology, as
  does the field of Earth, or whether a major fraction of the lines of
  force connect into extragalactic space. If the latter, then cosmic rays
  could be of extragalactic origin, or they could be of galactic origin,
  detained in the Galaxy by the scattering offered by hydromagnetic waves,
  etc. If, on the other hand, the field is largely closed, then cosmic
  rays cannot be of extragalactic origin (at least below 10<SUP>16</SUP>
  eV). They must be of galactic origin and escape because their collective
  pressure inflates the galactic field and they push their way out. This
  paper examines the structure of a galactic field that opens initially
  into intergalactic space and, with the inclusion of turbulent diffusion,
  finds no possibility for maintaining a significant magnetic connection
  with an extragalactic field. Unless some mechanism can be found, we
  are forced to the conclusion that the field is closed, that cosmic
  rays are of galactic origin, and that cosmic rays escape from the
  Galaxy only by pushing their way out.

Title: The Generation and Dissipation of Solar and Galactic Magnetic
    Fields
Authors: Parker, E. N.
Bibcode: 1973Ap&SS..22..279P
Altcode:
  Turbulent diffusion of magnetic field plays an essential role in
  the generation of magnetic field in most astrophysical bodies. This
  paper reviews what can be proved, and what can be believed, about
  the turbulent diffusion of magnetic field. Observations indicate the
  dissipation of magnetic field at rates that can be understood only
  in terms of turbulent diffusion. Theory shows that a largescale weak
  magnetic field diffuses in a turbulent flow in the same way that smoke
  is mixed throughout the fluid by the turbulence. The small-scale fields
  (produced from the large-scale field by the turbulence) are limited
  in their growth by reconnection of field lines at neutral points,
  so that the turbulent mixing of field and fluid is not halted by
  them. Altogether, it appears that the mixing of field and fluid
  in the observed turbulent motions in the Sun and in the Galaxy is
  unavoidable. Turbulent diffusion causes decay of the general solar
  fields in a decade or so, and of the galactic field in 10<SUP>8</SUP>
  10<SUP>9</SUP> yr. We conclude that continual dynamo action is implied
  by the observed existence of the fields.

Title: Cosmic Rays in the Outer Solar System (Article published
    in the Space Science Reviews special issue on 'Outer Solar System
    Exploration - An Overview', ed. by J. E. Long and D. G. Rea.)
Authors: Parker, E. N.
Bibcode: 1973SSRv...14..576P
Altcode:
  A space mission to Jupiter and Saturn, and beyond, provides an
  opportunity to explore the low energy galactic cosmic rays, which
  are largely excluded from the inner solar system by the outward sweep
  of the magnetic fields in the solar wind. The low energy cosmic rays
  are believed to be responsible for much of the heating of the gaseous
  disk of the galaxy, so a measurement of their intensity will have far
  reaching effects on theories of the interstellar gas and the evolution
  of the galaxy. The nuclear abundances, and in particular the presence
  or absence of high Z nuclei, will give critical information on the
  proximity of cosmic ray sources.

Title: The Reconnection Rate of Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1973ApJ...180..247P
Altcode:
  Solar flares, and the absence of intense small-scale magnetic fields
  in the turbulent solar photosphere, suggest that the reconnection
  rate, or merging speed, of two oppositely directed magnetic fields
  is of the general order of the Alfve'n speed. The fluid between
  the opposite fields escapes via the well-known interchange and kink
  instabilities, permitting rapid close approach of the fields, and
  merging rates probably of the order of 0.1 VA, or faster, in most
  cases. Hence reconnection is sufficiently rapid, with or without
  microinstabilities, that it plays a major role in solar flares and
  in the reduction of small-scale turbulent fields. Subject headings:
  flares, solar - hydromagnetics - magnetic fields, solar - turbulence

Title: Comments on the reconnexion rate of magnetic fields
Authors: Parker, E. N.
Bibcode: 1973JPlPh...9...49P
Altcode:
  The reconnexion rate of magnetic fields is crucial in understanding
  the fields found in turbulent flows in the solar photosphere and
  in the galaxy, and in flare phenomena. This paper examines the
  behaviour of magnetic fields in the neighbourhood of an X-type neutral
  point. The treatment is kinematical, specifying the velocity field v
  and constructing solutions to the hydromagnetic equation for B. The
  calculations demonstrate that the reconnexion rate is controlled by
  the diffusion in the near neighbourhood of the neutral point, and is
  not arbitrarily large, as has been suggested by similarity solutions
  of the complete field and fluid equations for vanishing diffusion

Title: A strategy for investigation of the outer solar system. Outer
    planets, their satellites, and particles and fields at great distances
    from the sun.
Authors: Münch, G.; Hunten, D. M.; Kliore, A. J.; Lewis, J. S.;
   McElroy, M. B.; Spencer, N. W.; Stone, P. H.; Wetherill, G. W.;
   Cameron, A. G. W.; Hubbard, W. B.; Murray, B. C.; Peale, S. J.; van
   Allen, J. A.; Axford, W. I.; Gulkis, S.; Kennel, C. F.; Montgomery,
   M. D.; Parker, E. N.; Sonett, C. P.; Stone, R. G.; Trainor, J. H.;
   Rea, D. G.; Long, J. E.; Padrick, B. D.
Bibcode: 1973SSRv...14..347M
Altcode:
  No abstract at ADS

Title: (Inaugural Lecture) What We Think We Know and Do Not Know
    About Solar Flares
Authors: Parker, E. N.
Bibcode: 1973str..conf....1P
Altcode:
  No abstract at ADS

Title: The Generation of Magnetic Fields in Astrophysical Bodies.IX. a
    Solar Dynamo Based on Horizontal Shear
Authors: Lerche, I.; Parker, E. N.
Bibcode: 1972ApJ...176..213L
Altcode:
  In view of the uncertainty in the angular velocity (r, 0) in the solar
  interior, we have worked out the general behavior of the solar dynamo
  for horizontal shear (() /aO) for comparison with the earlier models
  based on vertical shear (a /ar). The horizontal shear produces greater
  complexity, with the fields at the surface migrating toward the equator
  (for a uniform distribution of shear and cyclonic convection) and a
  layer of counter migrating fields at the bottom of the dynamo. More
  important, perhaps, the horizontal shear excites the even and odd
  modes equally, whereas vertical shear excites the odd mode before the
  even mode.

Title: Topological Dissipation and the Small-Scale Fields in
    Turbulent Gases
Authors: Parker, E. N.
Bibcode: 1972ApJ...174..499P
Altcode:
  It is shown that a large-scale magnetic field possesses a hydrostatic
  equilibrium only if the pattern of small-scale variations is uniform
  along the large-scale field. Thus equilibrium obtains only if the
  variations in the field consist of simple twisting of the lines,
  with the twists extending uniformly the full length of the field. Any
  more complicated topology, such as two or more flux tubes wrapped
  around each other to form a rope, or braided or knotted flux tubes,
  is without equilibrium, no matter what fluid pressures are applied
  along the individual lines of force. The result is rapid dissipation
  and field-line merging, which quickly reduces the topology to the
  simple equilibrium form. It follows from this general theorem that
  line merging has important consequences in turbulent fields. In
  spite of large magnetic Reynolds numbers of the individual eddies,
  the line merging reduces the small-scale fields in the turbulence
  below the value for equipartition with the turbulence. The effect has
  important astrophysical implications. It explains the absence of strong
  small-scale fields in the solar photosphere and in interstellar space
  in spite of the vigorous turbulence.

Title: Present Developments in Theory of the Solar Wind
Authors: Parker, E. N.
Bibcode: 1972NASSP.308..161P
Altcode: 1972sowi.conf..161P
  No abstract at ADS

Title: The dynamical behavior of the interstellar gas, field, and
    cosmic rays
Authors: Parker, E. N.
Bibcode: 1972cpp..conf..195P
Altcode:
  No abstract at ADS

Title: The Generation of Magnetic Fields in Astrophysical
    Bodies. VII. The Internal Small-Scale Fields
Authors: Lerche, I.; Parker, E. N.
Bibcode: 1971ApJ...168..231L
Altcode:
  The paper investigates the small-scale magnetic fields B generated,
  along with the large-scale magnetic fields B, by cyclonic turbulence
  and large-scale shear. The results are directly applicable to the
  problem of the generation of magnetic fields in the Galaxy,for
  which the observations show only the complexity of the small- and
  large-scale fields together, making it difficult to discover the actual
  configuration of the large-scale galactic field. The calculations
  show that the fluctuations in the generaijon of field in the Galaxy
  contribute a (( B)1) comparable to (B1).

Title: The Generation of Magnetic Fields in Astrophysical
    Bodies. VIII. Dynamical Considerations
Authors: Parker, E. N.
Bibcode: 1971ApJ...168..239P
Altcode:
  It is pointed out that the kinetic energy of the differential rotation
  of the Galaxy is sufficient to maintain generation of the galactic
  magnetic field for a period of time in excess of 10's years. In the
  Sun, on the other hand, the nonuniform rotation must be driven by
  thermal convective forces, etc. Magnetic buoyancy of the azimuthal
  field B is an important energy source in the Sun, nd contributes to
  the generation of the poloidal of the solar field. In the Galaxy
  the magnetic buoyancy of B contributes to the generation of the
  poloidal field, but if present observational estimates are correct,
  the inflation of the gaseous disk of the Galaxy by cosmic rays is a
  major source of the energy generating the poloidal component of the
  galactic poloidal field. The dynamical-dynamo equations are solved
  in the linear approximation to illustrate the direct generation of
  poloidal field from magnetic buoyancy and from cosmic-ray inflation.

Title: Recent Developments in Theory of Solar Wind
Authors: Parker, E. N.
Bibcode: 1971RvGSP...9..825P
Altcode: 1971RvGeo...9..825P
  No abstract at ADS

Title: The Generation of Magnetic Fields in Astrophysical
    Bodies.VI. Periodic Modes of the Galactic Field
Authors: Parker, E. N.
Bibcode: 1971ApJ...166..295P
Altcode:
  It is shown from the dynamo equations that the cyclonic turbulence
  and nonuniform rotation of the gaseous disk of the Galaxy generate
  magnetic field in both periodic and nonperiodic modes. Order-ofmagmtude
  estimates of the dynamo number suggest that the large-scale galactic
  field is generated in the lowest even periodic and/or nonperiodic
  modes. The characteristic period of the periodic mode is estimated at
  108 years. The large amplitude of the small-scale (lO pc) fluctuations
  in the internal field of the Galaxy make it difficult to compare the
  local field observations with theory to designate the mode of the
  large-scale field extending throughout the disk.

Title: The Generation of Magnetic Fields in Astrophysical
    Bodies. V. Behavior at Large Dynamo Numbers
Authors: Parker, E. N.
Bibcode: 1971ApJ...165..139P
Altcode:
  There is the theoretical possibility that some astrophysical objects may
  have large dynamo numbers, generating fields in high modes. The effect
  of the boundaries is diminished, and it is profitable to consider the
  fields in terms of the four basic wave modes of the dynamo. Normal
  incidence and reflection of dynamo waves from boundaries are worked
  out. Dynamo wave packets are discussed briefly, and a pseudoillustration
  of the solar dynamo is presented. The purpose of the calculations is
  to illustrate some of the behavior at large dynamo numbers, to aid in
  observational recognition.

Title: The Generation of Magnetic Fields in Astrophysical
    Bodies.IV. The Solar and Terrestrial Dynamos
Authors: Parker, E. N.
Bibcode: 1971ApJ...164..491P
Altcode:
  This paper explores the question of why the magnetic field of
  Earth is quasi-stationary in time while the field of the Sun is
  quasi-periodic. Both fields are believed to be produced by a combination
  of nonuniform rotation and cyclonic turbulence, or Rossby waves. The
  calculations show that small dynamo numbers lead to stationary states,
  producing a dipole when the dynamo number is negative in the northern
  hemisphere, as in Earth. The dynamo number in the northern hemisphere
  of the Sun is positive, but fails to produce the stationary quadrupole
  field because of the high dissipation associated with the thinness of
  the convective region. The lowest mode available in the Sun is periodic
  in time, with the fields an odd function of latitude, as observed. The
  calculations show that a modest increase in the dynamo number in the
  Sun excites the quadrupole mode. In view of the observed north-south
  asymmetry of the solar magnetic fields, the periodic quadrupole mode
  may be excited much of the time. The important consequences of magnetic
  variation of the Sun for the space environment of Earth suggest that
  a more general theoretical exploration of the dynamo equations in
  spherical coordinates should be carried out.

Title: The Dynamical Effects of Cosmic Rays in the Galaxy and the
    Generation of the Galactic Magnetic Field.
Authors: Parker, E. N.
Bibcode: 1971ICRC....8...95P
Altcode: 1971ICRC........95P; 1971ICRC...12h..95P
  No abstract at ADS

Title: The Generation of Magnetic Fields in Astrophysical
    Bodies. III. Turbulent Diffusion of Fields and Efficient Dynamos
Authors: Parker, E. N.
Bibcode: 1971ApJ...163..279P
Altcode:
  It is shown v formal calculation that the probability distribution of
  magnetic field carried in a turbulent fluid varies with the time in a
  manner identical with the probability distribution of a scalar field
  carried in the same turbulence. Then if Kraichnan's results are used
  for the diffusion of scalar fields, the effective turbulent-diffusion
  coefficient is 0.15 `u/k5, where u is the rms velocity of the turbulence
  and k0 is the wavenumber of the large eddies. In the gaseous disk of the
  Galaxy this gives 3 X I0 cm2 . It follows from this large value of that
  the galactic field cannot be primordial, but is automatically generated
  by the nonuniform rotation and turbulence throughout the gaseous disk.

Title: The Generation of Magnetic Fields in Astrophysical
    Bodies. II. The Galactic Field
Authors: Parker, E. N.
Bibcode: 1971ApJ...163..255P
Altcode:
  The gaseous disk of the Galaxy is subject to nonuniform rotation
  and internal turbulence. The rotation causes the turbulence to be
  cyclonic. Formal solution of the dynamo equations in a slab of gas,
  representing the galactic disk, produces regenerative modes, in which
  the aximutal field is an even function of the distance a from the
  central plane of the slab. Inclusion of the ` eddy diffusivity" of
  the turbulence in the dissipation terms of the dynamo equations gives
  growth times of 108 years. Hence we suggest that the magnetic field of
  the Galaxy is generated by the combination of nonuniform rotation and
  turbulence in the gaseous disk. The dynamo principle responsible for
  the magnetic field of Earth and of tlie Sun appears to be operative
  on a galactic scale, too.

Title: Magnetic fields in astrophysics.
Authors: Parker, E. N.
Bibcode: 1971JAP....42.1464P
Altcode:
  Magnetic fields appear in association with most astrophysical objects
  and spaces. Their general effect is to promote fast-particle and
  enhanced-temperature activity. It appears that the magnetic fields are
  generated by the combined nonuniform rotation and cyclonic turbulence of
  the objects. The nonuniform rotation shears the fields, producing strong
  fields in the azimuthal direction. The cyclonic turbulence interacts
  with the azimuthal field B<SUB>φ</SUB> generating azimuthal vector
  potential A<SUB>φ</SUB> at a rate described by the dynamo equation
  (∂/∂t-η▿<SUP>2</SUP>) A<SUB>φ</SUB> = ΓB<SUB>φ</SUB>, where
  Γ is essentially the cyclonic velocity of the turbulence. The fields
  of Earth, the Sun, and the galaxy appear to be generated in this way.

Title: Theoretical aspects of the worldwide magnetic storm phenomenon.
Authors: Parker, E. N.; Ferraro, V. C. A.
Bibcode: 1971HDP....49..131P
Altcode:
  No abstract at ADS

Title: Universal magnetic fields.
Authors: Parker, E. N.
Bibcode: 1971AmSci..59..578P
Altcode:
  No abstract at ADS

Title: The Generation of Magnetic Fields in Astrophysical
    Bodies. I. The Dynamo Equations
Authors: Parker, E. N.
Bibcode: 1970ApJ...162..665P
Altcode:
  The paper presents a formal derivation of the dynamo equations
  describing the generation of largescale magnetic fields by small-scale
  cyclonic turbulence (or convection) in a rotating fluid body. The
  derivation is based on the simple approximation that the individual
  turbulent cells are small and shortlived. The dynamo equations show
  that large-scale magnetic fields are generated at a very high rate,
  in periods comparable to the time of nonuniform rotation. The dynamo
  equations describe the generation of the quasi-steady field of Earth
  and the migratory field of the Sun, in characteristic times of 10 and
  10 years, respectively.

Title: Comments on `Steady state charge neutral models of the
    magnetosphere'
Authors: Lerche, I.; Parker, E. N.
Bibcode: 1970Ap&SS...8..140L
Altcode:
  No abstract at ADS

Title: The Origin of Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1970CoASP...2..127P
Altcode: 1970ComAp...2..127P
  No abstract at ADS

Title: The Origin of Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1970ApJ...160..383P
Altcode:
  No abstract at ADS

Title: on the Convection, Diffusion, and Adiabatic Deceleration of
    Cosmic Rays in the Solar Wind
Authors: Jokipii, J. R.; Parker, E. N.
Bibcode: 1970ApJ...160..735J
Altcode:
  We present a generalization and clarification of work on the transport
  of cosmic rays in the solar system. The general equations for the
  cosmic-ray density and flux, in the anisotropic-diffusion approximation,
  are derived in the frame of reference moving with the solar wind,
  and the transformation to the fixed frame is discussed. Only if
  the particle density varies smoothly with energy does one obtain a
  straightforward generalization of equations derived previously for
  isotropic diffusion. In this approximation we write down, for the first
  time, the correct differential equations for the particle density and
  flux for anisotropic diffusion. If the density varies sharply with
  energy, more complex integro-differential equations arise. We conclude
  that existing alternative derivations, based on the Boltzmann equation,
  are in general not adequate for either anisotropic-diffusion or energy
  transformations.

Title: The Origin of Solar Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1970ARA&A...8....1P
Altcode:
  No abstract at ADS

Title: The Origin and Dynamical Effects of the Magnetic Fields and
    Cosmic Rays in the Disk of the Galaxy
Authors: Parker, E. N.
Bibcode: 1970IAUS...39..168P
Altcode:
  No abstract at ADS

Title: Report on quasi-stationary modulation papers.
Authors: Parker, E. N.
Bibcode: 1970ICRC....5..341P
Altcode: 1970ICRC...11e.341P; 1969ICRC.......341P
  No abstract at ADS

Title: Interstellar Gas and Field
Authors: Parker, E. N.; Lerche, I.
Bibcode: 1969CoASP...1..215P
Altcode: 1969ComAp...1..215P
  No abstract at ADS

Title: The Occasional Reversal of the Geomagnetic Field
Authors: Parker, E. N.
Bibcode: 1969ApJ...158..815P
Altcode:
  It is presently believed that the geomagnetic field is generated by the
  combined effects of the cyclonic convective motions and the nonuniform
  rotation of the liquid core of Earth. Fossil magnetism shows that
  the fie'd remains steady for periods of the order of 1O6~1O7 years,
  and then, at apparently random times, reverses abruptly, thereafter
  remaining steady for another 1O~-1O~ years, etc. We do not believe
  that the reversal of the field is caused by a temporary change in
  the sign of the cyclonic or nonuniform rotations, since the signs of
  both are determined by the Coriolis forces of the rotating Earth. We
  demonstrate that a statistical fluctuation in the distribution of the
  fifteen to twenty cyclonic con~ vective cells in the core produces an
  abrupt reversal of the geomagnetic field. The simplest fluctuation
  lead- ing to reversal is a general absence of cyclones below about
  300 latitude for a time comparable to the life (`-%`1O~ years) of the
  individual cell. Assuming that the convective cells are statistically
  independent of each other, we estimate that such a fluctuation might
  occur once in 1O~ years. The simplicity of the mechanism recommends
  it as the explanation for the reversal of the field at random intervals

Title: Amplification of Weak Magnetic Fields in Turbulent Flow
Authors: Parker, E. N.
Bibcode: 1969ApJ...157.1119P
Altcode:
  The problem of a weak magnetic field carried in a turbulent-velocity
  field is considered under the circumstance that the velocity field is
  a prescribed random function of space and time. It is assumed that the
  time over which the velocity field is correlated with itself is very
  short. In this approximation the theory of random functions is used
  to show that the velocity field amplifies the magnetic field at all
  wave- numbers. Thus the calculation establishes that the large-scale
  components of a magnetic field in a turbu- lent-velocity field grow
  without limit as long as the velocity field is maintained. The unlimited
  amplifica- tion is of interest in astrophysical problems

Title: Origin of the Magnetic Field of the Galaxy
Authors: Parker, E. N.
Bibcode: 1969ApJ...157.1129P
Altcode:
  A recent formal calculation demonstrates that the individual Fourier
  components of a magnetic field are stochastic variables when the
  field is carried in a random turbulent velocity V~(r,t). The indi-
  vidual Fourier components random-walk, with the result that their
  mean squares increase with time. The calculation is applicable to
  the Galaxy when the magnetic field is sufficiently weak (B &lt; 1O~
  gauss). Application to the gaseous disk of the Galaxy indicates that a
  field of 1O~ gauss would be created in less than 1O~ years. The present
  orientation and large scale of the field along the galactic arm are
  presumably the result of the nonuniform rotation of the Galaxy. We
  conclude that turbulence is the most powerful source of magnetic field
  in the Galaxy, and that the present galactic magnetic field is the
  result of such turbulence. I. INTRODUCTIO

Title: Galactic Effects of the Cosmic-Ray Gas
Authors: Parker, E. N.
Bibcode: 1969SSRv....9..651P
Altcode:
  On an astronomical scale cosmic rays must be considered a tenuous and
  extremely hot (relativistic) gas. The pressure of the cosmic-ray gas
  is comparable to the other gas and field pressures in interstellar
  space, so that the cosmic-ray pressure must be taken into account
  in treating the dynamical properties of the gaseous disk of the
  galaxy. This review begins with a survey of present knowledge of the
  cosmic-ray gas. Then the kinetic properties of the gas are developed,
  followed by an exposition of the dynamical effects of the cosmic-ray
  gas on a large-scale magnetic field embedded in a thermal gas. The
  propagation of low-frequency hydromagnetic waves is worked out in the
  fluid approximation. The dynamical properties of the gaseous disk of
  the galaxy are next considered. The equations for the equilibrium
  distribution in the direction perpendicular to the disk are worked
  out. It is shown that a self-consistent equilibrium can be constructed
  within the range of the observational estimates of the gas density,
  scale height, turbulent velocity, field strength, cosmic-ray pressure,
  and galactic gravitational acceleration. Perturbation calculations then
  show that the equilibrium is unstable, on scales of a few hundred pc
  and in times of the order 2 × 10<SUP>7</SUP> years. The instability is
  driven about equally by the magnetic field and the cosmic-ray gas and
  dominates self-gravitation. Hence the instability dominates the dynamics
  of the interstellar gas and is the major effect in forming interstellar
  gas clouds. Star formation is the end result of condensation of the
  interstellar gas into clouds, indicating, then, that cosmic rays play
  a major role in initiating star formation in the galaxy. The cosmic
  rays are trapped in the unstable gaseous disk and escape from the disk
  only in so far as their pressure is able to inflate the magnetic field
  of the disk. The observed scale height of the galactic disk, the short
  life (10<SUP>6</SUP> years) of cosmic-ray particles in the disk of the
  galaxy, and their observed quiescent state in the disk, indicate that
  the galactic magnetic field acts as a safety valve on the cosmic ray
  pressure P so that P≅B <SUP>2</SUP>/8π. We infer from the observed
  life and quiescence of the cosmic rays that the mean field strength
  in the disk of the galaxy is 3 5 × 10<SUP>-6</SUP> gauss.

Title: Theoretical Studies of the Solar Wind Phenomenon
Authors: Parker, E. N.
Bibcode: 1969SSRv....9..325P
Altcode:
  This paper is a review of current theoretical topics concerning the
  solar wind. Broadly speaking the questions outstanding at the present
  time concern the loss of angular momentum to the sun, the origin of the
  fluctuations observed in the wind at the orbit of earth, conditions in
  the wind in regions yet unvisited by spacecraft (inside the orbit of
  Venus, beyond the orbit of Mars, and out of the plane of the ecliptic),
  conditions at the terminus of the wind, etc. The question of angular
  momentum loss is important in understanding the evolution of the sun
  to its present form with a slowly rotating surface. Evidence from both
  comet and spacecraft observations of the wind indicate that the rate
  at which angular momentum is being carried away by the solar wind is
  very large, of the order of 10<SUP>31</SUP> dyne/cm in the gas flow
  and half as much by the interplanetary magnetic field. But theory
  cannot account for more than about 10<SUP>30</SUP> dynes/cm in the
  gas without special assumptions. The fluctuations presently observed
  in the wind at the orbit of earth have scales ranging upward from
  10<SUP>2</SUP> km. Their presence is puzzling because fluctuations with
  scales less than about 10<SUP>6</SUP> km are not expected to survive
  from the sun. Presumably, therefore, the fluctuations are generated
  by the velocity differences of more than 100 km/sec in the wind from
  different regions in the solar corona and by instabilities produced
  by the anisotropy of the electrons of the wind plasma. Conditions in
  the wind at places far removed from the orbit of earth can be inferred
  from the behavior of cosmic rays. The evidence is that the wind becomes
  relatively placid beyond about 5 AU, extending from there out to 30 300
  AU without much small-scale turbulence. There are also some suggestions
  that the wind may perhaps be less turbulent toward the sun from 1 AU,
  and that the wind may be faster and more turbulent at higher solar
  latitudes. But the ambiguity of the situation does not permit a firm
  conclusion on this yet.

Title: Stochastic Aspects of Magnetic Lines of Force with Application
    to Cosmic-Ray Propagation
Authors: Jokipii, J. R.; Parker, E. N.
Bibcode: 1969ApJ...155..777J
Altcode:
  It is pointed out that magnetic lines of force in nature are generally
  stochastic and ergodic. Owing to unavoidable fluctuations in the field,
  adjacent lines of force random-walk away from each other. The stochastic
  properties of the lines of force in the astrophysical universe are
  related to the stochastic prop- erties of the (turbulent) velocity
  fields in which they are imbedded. The consequent random walk of the
  field lines is shown to contribute appreciably to K1, the coefficient
  for particle diffusion normal to the average field, with the result
  that the particles are spread across the average magnetic field
  much more rapidly than expected from the usual resonant scattering
  by small-scale irregularities. The Sun's extended magnetic field,
  traversed by both energetic solar particles and galactic cosmic rays,
  serves as an excellent illustration of these concepts. Application of
  the theory to the interplanetary magnetic fields shows that the random
  walk of the field lines is determined by the observed power spec-
  trum of the fluctuations in the magnetic field at zero frequency. The
  observed turbulent velocity field in the solar photosphere yields a
  random walk equal to that obtained from the observed power spectrum
  of the magnetic field. These two determinations of the random walk of
  the field lines, in turn, agree with the observed spread in solar
  longitude of promptly arriving solar cosmic rays. The observed
  shear planes and flux tubes of the "wet spaghetti" model of the
  interplanetary magnetic field are evidently a direct manifestation
  of the photospheric supergranulation. We also discuss the diffusion
  of cosmic rays in the interplanetary magnetic field observed near
  solar minimum. For protons with energies of 10 MeV and below, the
  ratio KL/KII at the orbit of the Earth becomes comparable to unity,
  instead of nearly zero as would be expected on the basis of resonant
  scat- tering alone. The contribution of the random walk to K~ is also
  significant at relativistic energies. Applica- tion to the theory of
  the diurnal variation of galactic cosmic rays agrees with observation
  both at `-~.-`1O MeV and at relativistic particle energies

Title: Cosmic-Ray Life and the Stochastic Nature of the Galactic
    Magnetic Field
Authors: Jokipii, J. R.; Parker, E. N.
Bibcode: 1969ApJ...155..799J
Altcode:
  We point out that the observed mean life for cosmic rays of ~ yrs
  is difficult to account for in conventional models of the galactic
  magnetic field. A stochastic model of the interstellar magnetic field
  is proposed, and is shown to provide a natural explanation of the
  cosmic-ray lifetimes. The random walk of magnetic lines of force,
  deduced from the observed turbulent motions of the gas and also from
  observa- tions of the polarization of starlight, leads to rapid motion
  of the cosmic-ray particles normal to the plane of the galactic disk

Title: Energetic solar particles.
Authors: Parker, E. N.
Bibcode: 1969AIQSY...4...57P
Altcode:
  No abstract at ADS

Title: Solar wind interaction with the geomagnetic field.
Authors: Parker, E. N.
Bibcode: 1969RvGSP...7....3P
Altcode: 1969RvGeo...7....3P
  No abstract at ADS

Title: Summary of symposium
Authors: Parker, E. N.
Bibcode: 1969sfsr.conf..412P
Altcode:
  No abstract at ADS

Title: Physical model of hydrodynamic turbulence.
Authors: Parker, E. N.
Bibcode: 1969PhFl...12.1592P
Altcode:
  A model for statistically isotropic homogeneous turbulence in an
  incompressible fluid is constructed, representing the turbulence as a
  superposition of individual vortex sheets. Each vortex sheet moves in
  the velocity field of the other sheets which have larger scale. Each
  sheet is stretched out, and intensified, until obliterated by viscosity
  at high wavenumber. The rate of stretching is related to the symmetric
  part of the strain tensor ∂ν<SUB>i</SUB>/∂κ<SUB>j</SUB>, which
  is postulated to be statistically independent of the antisymmetric
  part. Representing the turbulence by the usual energy spectrum function
  F(k) leads to a set of integrodifferential equations. Solution of
  the equations gives a spectrum which is in close agreement with
  experimental spectra of turbulence over both the inertial and
  viscous subranges, suggesting that the model may be of some real
  physical interest. The model is sufficiently explicit so as to give
  information on the correlation between different Fourier components
  of the turbulence. The calculations give the probability of finding
  a particular value of the vorticity or velocity at a given position
  and time in the turbulent field.

Title: Dynamical properties and effects of cosmic rays in the galaxy
Authors: Parker, E. N.
Bibcode: 1969pia..conf..237P
Altcode:
  No abstract at ADS

Title: The Dynamical Behaviour of the Gaseous Disk of the Galaxy
Authors: Parker, E. N.
Bibcode: 1969crsr.conf..202P
Altcode:
  No abstract at ADS

Title: The Dynamical State of the Interstellar Gas and
    Fields. VII. Disruptive Forces
Authors: Parker, E. N.
Bibcode: 1968ApJ...154..875P
Altcode:
  The important role played by disruptive forces in regulating the
  conversion of interstellar gas into stars is pointed out in the context
  of the present dynamical theory of the interstellar gas and fields

Title: The Dynamical State of the Interstellar Gas and
    Field.VI. Instability and Enhanced Diffusion in a Twisted Field
Authors: Lerche, I.; Parker, E. N.
Bibcode: 1968ApJ...154..515L
Altcode:
  The general instability of a magnetic field confined by the weight
  of thermal gas (through which the field threads) is investigated for
  a twisted field (v X B II B). The purpose is to see whether the asso-
  ciated enhanced ambipolar diffusion is seriously affected by the twist
  in the field. It was pointed out earlier that the enhanced diffusion
  (computed for an untwisted field) may contribute (a) to the escape of
  the interstellar magnetic field from the gas forming a star and (b)
  to the evolution of the gaseous disk of the Galaxy The calculations
  given in the present paper suggest that the twist in the field should
  in- crease the instability and the associated large wavenumbers,
  thereby increasing the enhanced ambipolar diffusion. We conclude that
  our earlier estimates of the enhanced ambipolar diffusion rate in the
  Galaxy may be on the conservative side

Title: The Dynamical State of the Interstellar Gas and
    Field.IV. Evolution of the Disk of Interstellar Gas
Authors: Parker, E. N.
Bibcode: 1968ApJ...154...49P
Altcode:
  It is shown that ambipolar diffusion, enhanced by the dynamical
  instability of the interstellar gas-field system, may permit the escape
  of a significant portion of the interstellar magnetic field from the
  disk of the Galaxy during the 1O'°-year life of the Galaxy. The result
  is a decrease in the scale height or thickness of the gaseous disk

Title: The Dynamical State of the Interstellar Gas and
    Field. V. Reduced Dynamical Equations
Authors: Parker, E. N.
Bibcode: 1968ApJ...154...57P
Altcode:
  The dynamical equations for a gas suspended on a horizontal magnetic
  field are simplified and re- duced by supposing that the Alfvén speed
  is large compared with the thermal velocity and that the scales are
  small compared with the scale height. The simplification renders the
  equations tractable in more complicated physical situations than the
  complete set of hydromagnetic equations used in some of the earlier
  investigations. A number of results for hydrostatic equilibrium,
  and for small perturbations of an equilibrium, are worked out to
  illustrate the properties of the approximate system of equations. Com-
  parison with the special cases treated from the complete equations
  indicates that most of the essential features of the dynamics appear
  to be retained by the simplified equations. The simplified equations
  are to be applied to more complicated cases in future papers

Title: Random Walk of Magnetic Lines of Force in Astrophysics
Authors: Jokipii, J. R.; Parker, E. N.
Bibcode: 1968PhRvL..21...44J
Altcode:
  We point out the importance of the random fluctuations in astrophysical
  magnetic fields, which lead among other things to rapid diffusion of
  energetic particles across the average magnetic field. Application
  to the interplanetary magnetic field leads to a theory in which the
  field-line random walk, measured by the observed power spectrum of
  field fluctuations, is in agreement with that deduced from the observed
  turbulent motions in the solar photosphere. The two determinations
  agree well with the recently observed spread in longitude of low-energy
  particles released at the sun.

Title: Dynamical Properties of Cosmic Rays
Authors: Parker, E. N.
Bibcode: 1968nim..book..707P
Altcode: 1968S&SS....7..707P
  No abstract at ADS

Title: Dynamical Properties of the Magnetosphere
Authors: Parker, E. N.
Bibcode: 1968ASSL...10....3P
Altcode: 1968phma.conf....3P
  No abstract at ADS

Title: Considerations of Solar Wind-Magnetosphere Interactions
Authors: Parker, Eugene N.
Bibcode: 1968epf..conf..357P
Altcode:
  No abstract at ADS

Title: The role of stochastic fields in admitting low-energy galactic
    cosmic rays to the solar system
Authors: Parker, E. N.
Bibcode: 1968JGR....73.6842P
Altcode:
  No abstract at ADS

Title: Non-Equilibrium and Enhanced Mixing at a Plasma-Field Interface
Authors: Lerche, I.; Parker, E. N.
Bibcode: 1967ApJ...150..731L
Altcode:
  No abstract at ADS

Title: Cosmic ray diffusion, energy loss, and the diurnal variation
Authors: Parker, E. N.
Bibcode: 1967P&SS...15.1723P
Altcode:
  The purpose of this paper is to consider a number of points pertaining
  to the origin of the observed mean diurnal variation of the cosmic
  ray intensity, which were not treated in the earlier papers on the
  subject. Following a brief review of the basic nature of the diurnal
  variation, the necessary diffusion across the lines of force is
  investigated. It is found that the values κ <SUB>⊥</SUB>/κ
  <SUB>‖</SUB> ≅ 10 <SUP>-2</SUP> deduced from the observed
  fluctuations inside the orbit of Earth give about the right amount of
  diffusion to account for the fact that the amplitude of the diurnal
  variation is approximately half the theoretical upper limit, which
  would apply if κ<SUB>⊥</SUB> were much larger. The calculations show
  that the geometry of the spiral form of the field beyond the orbit
  of Earth plays an essential role in providing sufficient diffusion
  across the lines of force. The calculations also show that variation
  in outer radius R and in κ <SUB>⊥</SUB>/κ <SUB>‖</SUB> due to
  changing wind conditions may contribute to some of the observed changes
  in the amplitude of the diurnal variation. The diurnal variation is
  rederived for steady uniform wind conditions in order to include the
  effect of adiabatic deceleration. The effect is the addition of a
  small diurnal component with an amplitude proportional to the radial
  cosmic ray gradient in space. The effect is only a few per cent of the
  total diurnal variation above 1 GeV, and so may be neglected there. The
  effect is large at low energies, but is not subject to observation. The
  principal observable steady diurnal variation is, then, the rotation
  of the cosmic rays with the Sun. Appendix II gives a summary of the
  motion of a particle in an idealized smooth spiral interplanetary field,
  with a discussion of the energy loss from adiabatic expansion.

Title: An Initial-Value Problem for Oscillations of the Interstellar
    Gas
Authors: Lerche, I.; Parker, E. N.
Bibcode: 1967ApJ...149..559L
Altcode:
  For a simple model of the interstellar-gas-magnetic-field system, in
  which the disk population of stars provides most of the gravity, it
  is demonstrated that a dispersion relation approach to the problem of
  small perturbations of the equilibrium state leads to unstable modes
  which possess a constant energy density at an infinite distance from
  the disk. Since one normally treats perturbations in which the energy
  density vanishes at infinity, rather than merely being bounded, we
  investigate an initial-value problem in which the energy density does
  vanish at infinity. It is shown, with one simple case, that an unstable
  situation still develops but that the perturbed quantities grow linearly
  with time rather than exponentially, as a normal mode analysis would
  indicate. It is further shown that one can still characterize the time
  scale for instability by the free-fall time so that conclusions drawn
  elsewhere by Parker remain valid.

Title: Energy changes of cosmic rays in the solar system
Authors: Jokipii, J. R.; Parker, E. N.
Bibcode: 1967P&SS...15.1375J
Altcode:
  The energy (in the fixed frame of reference) of a cosmic-ray particle
  with velocity w in the frame of the solar wind fluctuates between
  1/2M(w + v) <SUP>2</SUP> and 1/2M(w - v) <SUP>2</SUP> as the particle
  random walks in the magnetic field, where v is the wind velocity. This
  energy change cannot be treated as a simple Markov process, together
  with the random walk and adiabatic deceleration, in a fixed frame
  of reference. To describe the particle motion by a Fokker-Planck
  differential equation, the energy variable must be the particle
  energy in a frame of reference moving with the wind. The appropriate
  transformations of both the solutions and boundary conditions are
  presented to order v/ w. The corrections due to this effect are
  ∼10% for 1 MeV particles and correspondingly less for higher energy
  particles. The energy balance between the solar wind and cosmic rays
  is examined and is shown to depend in a fundamental manner on these
  energy transformations. Although the solar wind does net work on the
  cosmic-ray gas, no particle gains more than 2 Mvw kinetic energy and
  the few particles which penetrate deeply into the solar system suffer
  a net energy loss because of adiabatic deceleration.

Title: The Dynamical State of the Interstellar Gas and
    Field. II. Non-Linear Growth of Clouds and Forces in Three Dimensions
Authors: Parker, E. N.
Bibcode: 1967ApJ...149..517P
Altcode:
  The growth of the two-dimensional instability of a gas in a
  gravitational field g confining a horizontal magnetic field B is
  followed into the non-linear regime to provide an illustration of the
  formation of discrete gas clouds from a more uniform medium. A shock
  forms as the gas falls together, dissipating the energy and making
  the process irreversible. The effective force field of an element of
  gas (suspended on the lines of force of a horizontal magnetic field)
  is calculated in three dimensions. The force field is made up of
  an attractive force of the same form as gravity but stronger by the
  factor g2/GB2, and a force which extends undiminished along the lines of
  force passing near the element of gas. The latter dominates the former
  at large distances and is attractive on the lines of force through,
  and above and below, the element of gas, and repulsive along the lines
  of force passing beside the element of gas. The over-all effect is a
  strong attraction, accompanied by vigorous streaming of gas both toward
  and away from an established cloud. Clouds are expected to accumulate
  gas in such a way as to increase their vertical dimension relative to
  the transverse dimension g X B.

Title: The Dynamical State of the Interstellar Gas and
    Field. III. Turbulence and Enhanced Diffusion
Authors: Parker, E. N.
Bibcode: 1967ApJ...149..535P
Altcode:
  The dynamical instability of the interstellar gas, caused by the
  galactic cosmic rays and magnetic field, is examined for the purpose
  of gaining a more detailed understanding of the phenomenon. It is shown
  that a tissue of field, formed by superposing alternate layers of field
  at right angles to each other, fails to produce stability. It is shown
  that the instability develops very short wavelengths in the direction
  perpendicular to the galactic gravitational field g and magnetic field
  B. The result is that the interstellar gas must be in a continual
  state of turbulence and fragmentation down to scales of 1 pc or less,
  terminating only when the clouds become so dense that self-gravitation
  becomes dominant The turbulence and fragmentation enhance ambipolar
  diffusion to such an extent that the field escapes from the gas rapidly
  compared to the usual ambipolar rates It is suggested that this may
  contribute to the escape of the magnetic fields from the interstellar
  gas which forms stars

Title: Phenomena in Interplanetary Space. (Book Reviews: The Solar
    Wind. Proceedings of a conference held in Pasadena, California,
    in April 1964)
Authors: Parker, Eugene N.
Bibcode: 1967Sci...155..681P
Altcode: 1967Sci...155..681M
  No abstract at ADS

Title: Sun and Earth
Authors: Parker, E. N.
Bibcode: 1967easp.book...46P
Altcode:
  No abstract at ADS

Title: Disturbance of the Geomagnetic Field by the Solar Wind
Authors: Parker, E. N.
Bibcode: 1967pgp..conf.1154P
Altcode:
  No abstract at ADS

Title: The Dynamical State of the Interstellar Gas and Field
Authors: Parker, E. N.
Bibcode: 1966ApJ...145..811P
Altcode:
  There is now enough observational information available to show that
  the interstellar magnetic field in the general neighborhood of the
  Sun is, on the average, parallel to the plane of the Galaxy, with an
  average strength somewhere between 10-6 and tO-' gauss. This paper
  points out certain dynamical requirements for the existence of such
  a field. The paper is based on the assumption that the intergalactic
  medium, whatever it may be, exerts pressures on the Galaxy that
  are small compared to 10-12 dyne/cm'. It can then be shown that the
  galactic, or interstellar, magnetic field must be to the Galaxy by the
  weight of the gas threaded by the field and distributed throughout the
  disk of the Galaxy. It is then shown that the interstellar gas-field
  system is subject to a universal Rayleigh-Taylor instability of such
  a nature that the interstellar gas tends to concentrate into pockets
  suspended in the field. The cause of the instability may he thought
  of as a hydromagnetic self-attraction in the interstellar gas, which
  may be ten times larger than the gravitational self-attraction of
  the gas. It is this hydromagnetic self-attraction which produces the
  observed tendency of the interstellar gas to be confined in discrete
  clouds. The calculations and arguments do not restrict the over-all
  topology or the strength of the galactic field, which apparently must
  still be determined from observation.

Title: Non-Relativistic Equations of Bulk Motion of a Relativistic Gas
Authors: Lerche, I.; Parker, E. N.
Bibcode: 1966ApJ...145..106L
Altcode:
  The linearized equations of bulk motion of a gas, in which the
  pressure cannot be neglected compared to the rest energy of the gas,
  are deduced by taking moments of the collisionless Boltzmann equation
  in the absence of external forces. The problem is of interest because
  of its application to the cosmic-ray gas in the Galaxy.

Title: The Kinetic Properties of the Galactic Cosmic-Ray Gas
Authors: Parker, E. N.
Bibcode: 1966ApJ...144..916P
Altcode:
  The elementary formulae for the pressure and the speed of sound in
  a statistically isotropic homogeneous cosmic-ray gas are worked
  out. Cosmic-ray observations near Earth give a cosmic-ray energy
  density of 1.29 X 10- erg/cm3, a pressure of 0.45 x 1O dyne/cm2, and
  a compressibility P/ N = 0.66&gt;&lt; 10-li erg/cm3. There is reason
  to believe that the interstellar values are not significantly higher
  than near Earth.

Title: The effect of adiabatic deceleration on the cosmic ray spectrum
    in the solar system
Authors: Parker, E. N.
Bibcode: 1966P&SS...14..371P
Altcode:
  Cosmic rays in the magnetic fields carried in the solar wind are
  continually expanded and decelerated, in addition to being convected
  out of the solar system. The effect of the deceleration on the cosmic
  ray spectrum is calculated for the case that the outward convection
  of cosmic rays is small and for the case that the cosmic ray spectrum
  is a simple power law and the diffusion coefficient is independent of
  energy. The calculations are carried out for both particle momentum
  and energy. It is shown that a power law spectrum is preserved by the
  deceleration. It is shown that the deceleration contributes a decrease
  at high energies of about one third of the total modulation. Where the
  spectrum flattens out at lower energies, the deceleration produces an
  increase which partially cancels the reduction by convection.

Title: Dynamical Properties of Stellar Coronas and Stellar
    Winds. V. Stability and Wave Propagation
Authors: Parker, E. N.
Bibcode: 1966ApJ...143...32P
Altcode:
  The stability of an expanding corona against radial compressional
  waves is considered. It is shown that the linearized equations of
  motion are hyperbolic and the expanding corona is stable to the same
  general degree as a static atmosphere. Examples of wave propagation
  are worked out to illustrate the variation of amplitude of the waves
  with radial distance from the Sun.

Title: The Penetration of Galactic Cosmic Rays into the Solar System
Authors: Parker, E. N.
Bibcode: 1966sowi.conf..185P
Altcode:
  No abstract at ADS

Title: Particle Effects in the Geomagnetic Field
Authors: Parker, E. N.
Bibcode: 1966ASSL....5..302P
Altcode: 1966rtem.conf..302P
  No abstract at ADS

Title: Superthermal Hydromagnetic Waves.
Authors: Parker, E. N.
Bibcode: 1965ApJ...142.1086P
Altcode:
  The linearized of motion of a thermal gas and some very hot suprathermal
  gas, such as interstellar cosmic rays, in a uniform magnetic field are
  wntten down for plane waves in the low-frequency limit. The dispersion
  relation shows that there are three modes altogether: The conventional
  slow and fast hydromagnetic waves in the thermal gas are unaffected,
  except that there is a "hole" in the fast mode in the direction
  perpendicular to the magnetic field. The third mode is the suprathermal
  mode, representing waves in the suprathermal gas with essentially the
  velocity of sound in the suprathermal gas alone. The suprathermal
  mode fills the "hole" in the fast mode and is obviously the first
  disturbance to reach distant points following a supernova explosion.

Title: Dynamical Theory of the Solar Wind
Authors: Parker, E. N.
Bibcode: 1965SSRv....4..666P
Altcode:
  This paper is a review of the basic theoretical dynamical properties
  of an atmosphere with an extended temperature strongly bound by
  gravity. The review begins with the historical developments leading up
  to the realization that the only dynamical equilibrium of an atmosphere
  with extended temperature is supersonic expansion. It is shown that
  sufficient conditions for supersonic expansion are T(r) declining
  asymptotically less rapidly than 1/r, or the density at the base of
  the corona being less than N <SUB> b </SUB>given by (40) if no energy
  is available except through thermal conductivity, or the temperature
  falling within the limits given by (18) if T ∝ N <SUP> α-1</SUP>
  throughout the corona. Less extended temperatures lead to equilibria
  which are subsonic or static. The hypothetical case of a corona with no
  energy supply other than thermal conduction from its base is considered
  at some length because the equations may be solved by analytical
  methods and illustrate the transition from subsonic to supersonic
  equilibrium as the temperature becomes more extended. Comparison with
  the actual corona shows that the solar corona is actively heated for
  some distance into space by wave dissipation. The dynamical stability
  of the expanding atmosphere is demonstrated, and in a later section the
  radial propagation of acoustic and Alfvén waves through the atmosphere
  and wind is worked out. The calculations show that the magnetometer
  will probably detect waves more easily than the plasma instrument,
  but that both are needed to determine the mode and direction of the
  wave. An observer in the wind at the orbit of Earth can “listen”
  to disturbances generated in the corona near the sun and in turbulent
  regions in interplanetary space. The possibility that the solar corona
  is composed of small-scale filaments near the sun is considered. It is
  shown that such filamentary structure would not be seen at the orbit
  of Earth. It is pointed out that the expansion of a non-filamentary
  corona seems to lead to too high a calculated wind density at the
  orbit of Earth to agree with the present observations, unless T(r)
  is constant or increases with r. A filamentary corona, on the other
  hand, would give the observed wind density for declining T(r). It
  is shown that viscosity plays no important role in the expansion
  of an atmosphere either with or without a weak magnetic field. The
  termination of the solar wind, presumably between 10 10<SUP>3</SUP>
  AU, is discussed briefly. The interesting development here is the
  interplanetary L <SUB>α</SUB>recently observed, which may come from the
  interstellar neutral hydrogen drifting into the outer regions of the
  solar wind. Theory is at the present time concerned with the general
  dynamical principles which pertain to the expansion equilibrium of an
  atmosphere. It is to be expected that the rapid progress of direct
  observations of the corona and wind will soon permit more detailed
  studies to be carried out. It is important that the distinction between
  detailed empirical models and models intended to illustrate general
  principles be kept clearly in mind at all times.

Title: Cosmic Rays and Their Formation of a Galactic Halo.
Authors: Parker, E. N.
Bibcode: 1965ApJ...142..584P
Altcode:
  It is demonstrated that a magnetic gas cloud confined by gravity has
  no equilibrium configuration if cosmic rays are generated within it. By
  application of the theorem to the Galaxy, it is shown that cosmic rays
  lead to inflation of the galactic magnetic fields, producing a halo of
  cosmic rays and field around the Galaxy. Present observational estimates
  of cosmic-ray life, magnetic-field strength, etc.,indicate an outward
  inflation rate of the order of 102 km/sec, although this number may
  be revised with improved observations. This cosmic-ray halo extends
  far out from the disk and nucleus of the Galaxy, presumably limited
  by instabilities which eventually free the cosmic rays and fields at
  a great distance. The field inflation acts as a pressure regulator on
  the cosmic rays generated in the galactic disk and nucleus, so that
  the life of a cosmic-ray particle in the disk of the is determined
  mainly by the rate of generation of cosmic rays. Present estimates of
  the cosmic-ray life are based on the rather uncertain value of the
  density of interstellar gas. The gas is intimately associated both
  with the dynamics of the galactic fields and the calculated rate of
  cosmic-ray production.

Title: Dynamical Properties of Stellar Coronas and Stellar Winds,
    IV. The Separate Existence of Subsonic and Supersonic Solutions.
Authors: Parker, E. N.
Bibcode: 1965ApJ...141.1463P
Altcode:
  The dynamical equations are considered for a stationary stellar corona
  whose energy is supplied only by thermal conduction from its base and
  which is surrounded by a cold vaccuum. The density and temperature
  at the base of the corona are denoted by N0 and T0, respectively. It
  is shown that subsonic and supersonic expansion of such a minimum
  stellar corona are separated by a density N (To): If N0 &lt; NB(To),
  the expansion is supersonic; if N0&gt; NB(To), the expansion is
  subsonic. Observations suggest that T0 1 X 100 K for the quiet solar
  corona, so that NB(To) 3 X 1010/ cm3. The observed densities are
  108-109/cm3, requiring supersonic expansion. Detailed comparison of
  this theoretical corona of minimum heating with the observed solar
  temperatures, densities, and expansion velocity suggests that the
  solar corona is, in fact, heated in depth.

Title: General dynamical effects of cosmic rays in the Galaxy.
Authors: Parker, E. N.
Bibcode: 1965ICRC....1..126P
Altcode: 1965ICRC....9..126P
  No abstract at ADS

Title: The passage of energetic charged particles through
    interplanetary space
Authors: Parker, E. N.
Bibcode: 1965P&SS...13....9P
Altcode:
  The passage of cosmic ray particles and energetic solar particles
  through interplanetary space is illustrated with a number of
  idealized examples. The formal examples are worked out from the
  condition that energetic particles in interplanetary space random
  walk in the irregularities in the large-scale interplanetary magnetic
  field. The irregularities move with approximately the velocity of the
  solar wind. The classical probability distribution is describable
  by a Fokker-Planck equation. A general expression for the particle
  diffusion coefficient k<SUB>ij</SUB> is worked out, including
  both scattering in magnetic irregularities and systematic pressure
  drifts. Magnetometer data from Explorer XVIII is presented to show
  the close average adherence of the quiet-day interplanetary magnetic
  field to the theoretical spiral angle, and to show the tendency
  for particles to move more freely along the field than across,
  k<SUB>∥</SUB> &gt; k<SUB>⊥</SUB>. The observed fields show that
  the diffusion coefficient is of the order of 10 <SUP>21</SUP>-10
  <SUP>22</SUP> cm <SUP>2</SUP>/sec, as had been estimated from
  earlier cosmic ray studies. A middle value of 3 × 10 <SUP>21</SUP>
  cm <SUP>2</SUP>/sec suggests a cosmic ray density gradient of about 10
  per cent per a.u. across the orbit of Earth. Direct observations of the
  interplanetary magnetic field afford the possibility for quantitative
  estimate of K<SUB>ij</SUB> as a function of particle energy. The
  first example to be considered is isotropic diffusion in a spherical
  region r &lt; R with uniform radial wind velocity v for the purpose
  of illustrating the general nature and duration of the passage of a
  cosmic ray particle through the solar system. It is shown that the
  cosmic ray density reduction is of the order of exp (- vR/ k), and,
  hence, that during the years of solar activity vR/ k is not less than
  about 1 for protons of one BeV or so. It follows from this that the
  galactic cosmic ray particles will generally have spent several days
  in the solar system by the time they are observed. During this time
  they are in the expanding magnetic fields carried in the solar wind
  and are adiabatically decelerated, losing 15 per cent or more of their
  energy by the time they are observed. The energy distribution is shown
  for particles starting all with the same energy T<SUB>0</SUB> from
  interstellar space. The incoming probability wave of a single particle
  is computed as a function of time, showing how the particle is swept
  back by the wind. The converse problem of energetic solar particles
  is illustrated. The solar particles may typically lose half their
  initial energy before escaping into interstellar space. The outward
  motion of the wind displaces their probability distribution outward so
  that ultimately the maximum solar particle intensity may lie beyond the
  orbit of Earth. The outward motion of the wind steepens the decline of
  the solar particle intensity. The steady-state cosmic ray intensity is
  calculated throughout the spherical region r &lt; R supposing a uniform
  cosmic ray density N<SUB>0</SUB> to obtain in interstellar space. The
  calculation is carried out for isotropic K<SUB>ij</SUB>, which would
  obtain if the magnetic irregularities were of large amplitude and
  of a scale not exceeding the radius of gyration of the cosmic ray
  particles, and for anisotropic k<SUB>ij</SUB> with k<SUB>∥</SUB>
  ≫ k<SUB>⊥</SUB>, which obtains when the field is relatively
  smooth. (The observations at sunspot minimum suggest k<SUB>∥</SUB> ≫
  k<SUB>⊥</SUB> at the orbit of Earth.) The particles diffuse only along
  the spiral lines of force when k<SUB>∥</SUB> ≫ k<SUB>⊥</SUB>,
  so their path in and out of the solar system is much longer than when
  K<SUB>ij</SUB> is isotropic. The result is a much greater reduction
  of the cosmic ray intensity for a given vR/| K<SUB>ij</SUB>|. There
  is no direct observational information on K<SUB>ij</SUB> beyond the
  orbit of Earth, where the intensity reduction takes place. Indirect
  information is available, however. There is the fact that the intensity
  of energetic solar particles at Earth often decays as t<SUP>- g</SUP>
  with g = 1·5-2·0. It is shown that in order for this to follow, it is
  necessary that | K<SUB>ij</SUB>| ∞ r<SUP>s</SUP> with s = 0·0-0·5 if
  k<SUB>ij</SUB> is isotropic, and s = 2·0-2·5 if k<SUB>∥</SUB> ≫
  k<SUB>⊥</SUB>. That is to say, if K<SUB>ij</SUB> should continue to
  be as anisotropic beyond Earth as it is observed to be near Earth, then
  the diffusion must increase rapidly with distance from the Sun. These
  qualitative features should be easily detectable with particle, field,
  and plasma observations beyond the orbit of Earth.

Title: On the Existence of Slow Solutions in Coronal Hydrodynamics.
Authors: Parker, E. N.
Bibcode: 1965ApJ...141..322P
Altcode:
  No abstract at ADS

Title: Some remarks on the influence of the granulation on the
    magnetic field
Authors: Parker, E. N.
Bibcode: 1965IAUS...22..232P
Altcode:
  No abstract at ADS

Title: A brief outline of the development of cosmic ray modulation
    theory
Authors: Parker, E. N.
Bibcode: 1965ICRC....1...26P
Altcode: 1965ICRC....9...26P
  No abstract at ADS

Title: Coronal Expansion and Solar Corpuscular Radiation
Authors: Parker, E. N.
Bibcode: 1965ASSL....3...99P
Altcode: 1965pss..conf...99P
  No abstract at ADS

Title: A Mechanism for Magnetic Enhancement of Sound-Wave Generation
    and the Dynamical Origin of Spicules.
Authors: Parker, E. N.
Bibcode: 1964ApJ...140.1170P
Altcode:
  It is pointed out that a vertical magnetic field through an atmosphere
  with a small scale height greatly tahances the generation of sound
  (fast-mode) waves in the fluid motions in the atmosphere. The fluid
  motions become a monopole, rather than the usual quadrupole, source of
  radiation. The sound waves ropagate principally in the upward direction
  along the field. It is suggested that this mechanism, apart from its
  other applications, operates in the plage areas on the Sun and is
  responsible for the spicules.

Title: Review of Publications- Interplanetary Dynamical Processes
Authors: Parker, E. N.
Bibcode: 1964JRASC..58..235P
Altcode:
  No abstract at ADS

Title: Discussion of Paper by E. J. Stegelmann and C. H. von
    Kenschitzki `On the Interpretation of the Sudden Commencement of
    Geomagnetic Storms'
Authors: Parker, E. N.; Dessler, A. J.
Bibcode: 1964JGR....69.3745P
Altcode:
  It was pointed out some years ago [Dessler et al. 1960] that a major
  part of the rise time of a sudden commencement can be accounted for
  as the period of time in which the enhanced solar wind sweeps over
  the outer boundary of the geomagnetic field, plus the difference in
  propagation time from different points on the boundary. The dimensions
  of the outer boundary of the geomagnetic field are of the order of
  10<SUP>5</SUP> km, so that an enhanced wind of 10<SUP>3</SUP> km/sec
  characteristically takes about 10<SUP>2</SUP> seconds to engulf the
  field and enhance the compression of the field. Typical propagation
  times within the field differ by 10<SUP>2</SUP> seconds. The basic idea
  was simply that the compression of the geomagnetic field at the surface
  of the earth results from the algebraic sum of all the compressive
  forces exerted by the wind on the outer boundary of the field [Parker,
  1958]. Any changes in the compressive forces on the outer boundary are
  communicated inward at about the Alfvén velocity [Francis et al.,
  1959]. Enhanced compression of the boundary starts somewhere on the
  solar side, at which time a slight increase in compression begins to
  propagate through the geomagnetic field as a hydromagnetic wave. With
  the passage of time more and more of the boundary is compressed as the
  enhanced wind sweeps by in space. The rising compression communicates
  throughout the field with the Alfvén speed, and levels off only after
  the enhanced wind fully encloses the geomagnetic field.

Title: Theory of streaming of cosmic rays and the diurnal variation
Authors: Parker, E. N.
Bibcode: 1964P&SS...12..735P
Altcode:
  The motion of charged particles in magnetic fields is reviewed
  for the purpose of understanding the observed net streaming of
  cosmic rays through interplanetary space. It is shown that the
  large-scale fields (which often reverse) give no steady streaming by
  themselves. Small-scale irregularities in the large-scale fields can
  give steady radial streaming which in the vicinity of Earth is some
  small fraction of the solar wind velocity. A large-scale field at
  the orbit of Earth with sufficient magnetic irregularity beyond gives
  an azimuthal streaming with the velocity of rigid rotation with the
  Sun. It is suggested that this rigid rotation is the origin of the
  observed diurnal variation.

Title: Formation of Massive Quasi-Stellar Objects.
Authors: Miller, R. H.; Parker, E. N.
Bibcode: 1964ApJ...140...50M
Altcode:
  Enhancement of evaporation from a star cluster through the operation
  of co-operative phenomena is suggested as a possible mechanism for
  the formation of compact massive objects from star clusters in times
  of the order of 1016 years.

Title: Coronal expansion and solar corpuscular radiation
Authors: Parker, E. N.
Bibcode: 1964P&SS...12..451P
Altcode:
  No abstract at ADS

Title: The Scattering of Charged Particles by Magnetic Irregularities
Authors: Parker, E. N.
Bibcode: 1964JGR....69.1755P
Altcode:
  The equations of motion of a charged particle are integrated through
  an irregularity in a large-scale magnetic field. The scattering of
  the particle is shown to diminish as the cyclotron radius of the
  particle becomes either large or small compared to the scale of the
  irregularity and to have a maximum when the radius is comparable to
  the scale. When the cyclotron radius is large, the order of magnitude
  of the scattering depends on the number of sequential reverse bends in
  the lines of force through the magnetic irregularity. It is important
  for the understanding of modulation of the cosmic-ray intensity by
  the solar wind to determine the degree of correlation between adjacent
  bends in the irregularities in the interplanetary magnetic field.

Title: The Perturbation of Interplanetary Dust Grains by the Solar
    Wind.
Authors: Parker, E. N.
Bibcode: 1964ApJ...139..951P
Altcode:
  It is expected that photoelectric emission from the interplanetary
  dust grains leads to a positive charge the order of 10 volts on each
  grain. The Lorentz forces exerted on this charge by the magnetic
  fields . ied in the solar wind produce large perturbations in the
  Kepler orbits of the grains. On the assumpn that the sign of the
  interplanetary magnetic field reverses every few days, it is shown
  that the orbital lination of particles with radii equal to or smaller
  than about 1 X 10- cm at the orbit of Earth is atly increased by the
  Lorentz forces The importance of the Lorentz perturbation increases
  with the tance from the Sun.

Title: Dynamical Properties of Stellar Coronas and Stellar
    Winds. III. The Dynamics of Coronal Streamers.
Authors: Parker, E. N.
Bibcode: 1964ApJ...139..690P
Altcode:
  Observations suggest that the solar corona may perhaps consist of
  thin radial filaments and streamers, rather than bring an amoiphous
  atmosphere. The filaments and streamers presumably are confined by the
  magnetic field, along whose lines 9f force they lie. To investigate the
  consequences of a filamentary corona for the solar wind, the dynamics
  of an idealized cona composed of gaseous streamers, with vacuum between
  the streamers, is worked out neglecting solar rotation, etc. The pnndpal
  conclusions are that the streamers occupy most of space at large radial
  distance from the Sun, no matter how small a fraction they may occupy
  at the Sun; the velocity of the solar wind is not greatly affected by
  filamentary structure for a given coronal temperature distribution; the
  mean-wind density is not affected by more than a factor of 2. Mtogether,
  then, except for the presence of some thin interstreamer regions, there
  is no great effect of a filamentary structure on the mean values of the
  solar-wind velocity and density at large distance from the Sun. The
  possibility of instability of coronal streamers is looked into, and
  it is shown that, if the corona is composed principally of streamers,
  the Helmholtz instability may be expected to disorder and mix up the
  streamer and interstreamer regions beyond some distance 0 (1 a.u.) from
  the Sun, which might perhaps be the origin of some of the disorder
  observed by Mariner. More quantitative observational information of
  the solar corona and/or of the structure of the solar wind close to
  the Sun will have to be available before quantitative statements can
  be made concerning the role of streamers in the solar wind.

Title: Dynamical Properties of Stellar Coronas and Stellar
    Winds. I. Integration of the Momentum Equation.
Authors: Parker, E. N.
Bibcode: 1964ApJ...139...72P
Altcode:
  The hydrodvnamic momentum and mass flow equations are integrated
  for a stellar corona with spherical symmetry about the center of
  the star. The coronal temperature is taken to be a known function
  T(r) of radial distance. The general properties of the equations are
  discussed, and it is shown that if the corona is tightly bound by the
  solar gravitational field, so that the thermal elodty is small compared
  to the gravitational escape velocity, and if the coronal temperature
  declines outward more slowly than 1/r, then the corona is quasi-static
  at its base and expands to supersonic velocity in space. No alternative
  is available. The stellar mass loss resulting from the expansion is
  determined by the coronal temperature between the base of the corona
  and the point at which the flow becomes supersonic. The amount by
  which the velocity of the resulting stellar wind exceeds the thermal
  velocity in the corona depends principally upon the temperature beyond
  the point where the flow becomes supersonic.

Title: Dynamical Properties of Stellar Coronas and Stellar
    Winds. II. Integration of the Heat-Flow Equation.
Authors: Parker, E. N.
Bibcode: 1964ApJ...139...93P
Altcode:
  The temperature T(r) in a stellar corona is computed under the
  circumstances that energy is supplied outward from the base of the
  corona only by thermal conduction. The heat-flow equation is solved
  analytically under a variety of circumstances. It is shown that the
  energy flow to infinity is non-vanishing for finite coronal density
  and thermal conductivity. The temperature declines less rapidly than
  1/r, and a supersonic stellar wind is the only available solution of
  the equations compatible with negligible pressure at r = A variety of
  asymptotic cases are worked out to illustrate some of the temperature
  proffles T(r) to be expected under various circumstances. For instance,
  in a corona of very low density the energy consumed by expansion of
  the corona can be neglected and T(r) , as in Chapman's original static
  coronal model. The result is a supersonic stellar wind with a velocity
  v( ) of the same order as the gravitational escape velocity 21!2w. In
  a corona with medium density and sufficiently low temperature that
  v('0) is small compared to w, a near region, in which T(r) extends
  for some distance outward from the star before the far region, T(r)
  , takes over. The result is a supersonic stellar wind velocity v(
  ) of the same order as the characteristic thermal velocity C0 at
  the base of the corona. In a corona which is exceedingly dense, an
  intermediate region in which T(r) appears between the near and the
  far regions, which has the result of extending to large distance the
  point at which the coronal expansion becomes supersonic. In a corona
  which is exceedingly hot (cc w) the expansion becomes so violent that
  thermal conduction becomes negligible and the behavior of the corona
  is approximately adiabatic. It is shown that any effect which tends to
  reduce the thermal conductivity of the coronal gases at large distance
  from the star has the effect of enhancing the velocity of the stellar
  wind. Comparison with Chamberlain's earlier discussion of the solution
  of the momentum and heat-flow equations in his "solar-breeze" model
  shows that he made two self-consistent errors in his assumption that
  the energy flux in the solar wind is identically zero and that the
  gas motion is adiabatic at large radial distances from the sun. It
  is shown that neither assumption is correct in a corona of finite
  density. It is shown, however, that the analytical form T(r) 1/r
  suggested by Chamberlain is obtained in the limit as the density of
  the corona is made large without limit, in which case all motion in the
  corona approaches zero. Application of the solutions of the heat-flow
  equation to the sun-assuming that the solar corona is heated solely
  by thermal conduction-show that at least under present conditions the
  solar corona and wind lie in the middle ground between high and low
  density and temperature. Assuming that they have coronas heated solely
  by conduction it is suggested that some of the giant stars with the low
  gravitational escape velocities, may fall into the high-density case,
  and certain dwarfs into the low-density case. Some of the very active
  stars may fall into the high-temperature quasi-adiabatic case.

Title: Coronal Expansion and Solar Corpuscular Radiation
Authors: Parker, E. N.
Bibcode: 1964rege....1...99P
Altcode:
  No abstract at ADS

Title: Comments on Understanding the Solar Flare
Authors: Parker, E. N.
Bibcode: 1964NASSP..50..417P
Altcode: 1964psf..conf..417P
  No abstract at ADS

Title: Kinematical Hydromagnetic Theory and its Application to the
    Low Solar Photosphere.
Authors: Parker, E. N.
Bibcode: 1963ApJ...138..552P
Altcode:
  The magnetic field B is computed from the hydromagnetic equations for a
  variety of given velocity fields';. The velocity fields are classified
  as turbulent if their time correlation extends no more than their scale
  a divided by their characteristic velocity v. The velocity fields are
  classified as persistent if their time correlation extends beyond a/v
  but is short compared with the magnetic diffusion time a2/X (X = c2/4ir
  , and as stationary if their time correlation extends beyond a2/X. It
  is shown that turbulent fluid motions in the solar photosphere generate
  r.m.s. fields which are a few times the large-scale field strength B0 in
  the photosphere. Where B0&gt; 20 gauss, this leads to equipartition of
  energy between the turbulent magnetic and velocity fields. It is &amp;
  njectured that, since plages occupy the areas on the solar surface where
  B0&gt; 20 gauss, there may be some connection between equipartition and
  plage formation. It is shown that motions tend to draw the field into
  concentrated sheets and filaments. The observed supergranulation in the
  solar atmosphere tends to concentrate vertical magnetic fields around
  the edges of the cells, where the field density may become 102 times
  larger than in the interior of the cell. It is shown that stationary
  motions tend to exclude the magnetic field from the region of fluid
  motion. A number of examples are given to show the distortion of the
  field by the forces exerted by the fluid diffusing through it. It is
  to be hoped that observations will yield simultaneous velocity and
  magnetic-field maps so that quantitative comparison can be made with
  the expected theoretical results.

Title: A Kinematical Theory of Turbulent Hydromagnetic Fields.
Authors: Parker, E. N.
Bibcode: 1963ApJ...138..226P
Altcode:
  A kinematical theory is developed for the r.m.s. magnetic fields
  produced by the interaction of turbulent eddies, of scale a and
  velocity v, with a large-scale weak magnetic field B0. The principal
  interest lies in the small-scale magnetic field generated by the
  observed photospheric granules in the observed large-scale photospheric
  magnetic fields. The theory considers how a rope of magnetic flux is
  both lengthened and widened by the velocity gradients in statistically
  stationary, isotropic, homogeneous turbulence in which the velocity
  fields are given. Both the amplification and diffusion of the magnetic
  field are then computed from the proportions of the rope of flux,
  employing the usual statistical assumption that moments of order 2n can
  be expressed in terms of the product of n factors of second moments. The
  conclusion is that a weak field B0 can be amplified by a factor of the
  order of R1/4/ln R, where R is the magnetic Reynolds number. in the
  solar photospheric granules this amounts to amplification by a factor
  less than 10, so that the small-scale r m 5. fields resulting in quiet
  regions where B0 __ 1 gauss are far below the value for equipartition
  of energy with the velocity field.

Title: The Solar-Flare Phenomenon and the Theory of Reconnection
    and Annihiliation of Magnetic Fields.
Authors: Parker, E. N.
Bibcode: 1963ApJS....8..177P
Altcode:
  The paper presents a study of the observations and theory which are
  relevant to the presently popular belief that the solar-flare phenomenon
  is a direct consequence of the annihilation of magnetic fields on the
  sun. There is very little in the observations to support such views. A
  systematic study of the known theoretical mechanisms for the diffusion,
  reconnection, and annihilation of magnetic fields is presented. The
  mechanisms discussed are Joule dissipation, ambipolar diffusion,
  and various forms of Sweet's mechanism. It is shown that Sweet's
  mechanism is much more effective in a highly compressible medium if
  the merging magnetic fields are exacily antiparallel. None of the known
  mechanisms are sufficiently rapid to account for the solar flare from
  the annihilation of magnetic fields. Errors and omissions in earlier
  discussions of the problem are cited. Since no possible energy source
  other than magnetic fields has yet been developed, the question of
  field annihilation remains both open and pressing. The possibilities of
  runaway electrons and hydrodynamic instability, as means for hastening
  magneticfield annihilation, are considered. It is shown that there is no
  reason to expect runaway electrons and no effective instability unless
  the fields are exactly antiparallel. The observational and theoretical
  difficulties with the hypothesis of magnetic-field annihilation suggest
  that other alternatives for the flare must be explored.

Title: Discussion of Paper by L. M. Noble and F. L. Scarf,
    `Hydrodynamic Models of the Solar Corona'
Authors: Parker, E. N.
Bibcode: 1963JGR....68.1769P
Altcode:
  In a recent paper entitled `Hydrodynamic models of the solar corona'
  Noble and Scarf [1962] discuss the many theoretical models of the
  solar corona that have been worked out over the past few years. Some of
  the calculations they present are of interest, but unfortunately the
  value of the calculations is obscured by the extraordinary physical
  interpretations the authors associate with them. For instance, Noble
  and Scarf remark that `the models with conductive [heat] flow and no
  inner heat source lead to density distributions in fair agreement with
  zodiacal light observations, but no solar wind is obtained'. They seem
  to be unaware that Chamberlain [1961], whose paper on conductive flow
  they quote, had arbitrarily to inhibit the thermal conductivity by a
  factor of 8 to obtain agreement with the zodiacal light. Uninhibited
  thermal conduction in a 2×10<SUP>6</SUP> deg K corona supplies energy
  in the amount that seems to be required for the observed solar wind
  [Bridge et al., 1962].

Title: Theory of Solar Wind
Authors: Parker, E. N.
Bibcode: 1963ICRC....1..175P
Altcode: 1963ICRC....8a.175P
  No abstract at ADS

Title: Plasma Dynamics in Astrophysics and Geophysics (Notes by
    M. Turoff and A. Skalafuris)
Authors: Parker, E. N.
Bibcode: 1963ambp.book....1P
Altcode:
  No abstract at ADS

Title: Comments on Coronal Heating.
Authors: Parker, E. N.
Bibcode: 1963IAUS...16...11P
Altcode:
  No abstract at ADS

Title: Interplanetary dynamical processes.
Authors: Parker, Eugene Newman
Bibcode: 1963idp..book.....P
Altcode: 1963QB505.P3.......
  No abstract at ADS

Title: Kinetic properties of interplanetary matter
Authors: Parker, E. N.
Bibcode: 1962P&SS....9..461P
Altcode:
  The paper is a review of present estimates of the kinetic and transport
  properties of the interplanetary medium. It is pointed out that the
  effective mean free paths of interplanetary ions and electrons are
  effectively small compared to the scale of the system either because
  of Coulomb collisions or because of dynamical instability of the
  gas. Numerical expressions are given for the mean free path for Coulomb
  collisions, the electrical conductivity, the thermal conductivity, the
  viscosity, electromagnetic emission rates, recombination and ionization
  times and the charge exchange cross-sections. The magnetic Reynolds
  number of the solar wind proves to be large, the Reynolds number is
  not very large and the Prandtl number is small. All stationary atoms
  and ions are swept out of the solar system by the solar wind. It is
  pointed out that the quiet day cosmic ray density in interplanetary
  space increases the speed of sound beyond the orbit of Earth, reaching
  10 <SUP>2</SUP> km/sec at 50 a.u. if the solar wind should extend
  that far. Energetic particles from the sun have an effect which may
  be much larger. The abundance of heavy ions in the solar wind may be
  significantly below the solar abundance because of diffusion in the
  solar corona.

Title: Interplanetary Dynamical Processes; The Solar Wind and
    Interplanetary Fields
Authors: Parker, E. N.
Bibcode: 1962pss..conf...23P
Altcode:
  No abstract at ADS

Title: Dynamics of the Geomagnetic Storm
Authors: Parker, E. N.
Bibcode: 1962SSRv....1...62P
Altcode:
  This paper is intended as a critical review of current ideas concerning
  the mechanisms responsible for the geomagnetic storm. The dynamical
  theory of the geomagnetic storm phenomenon is formulated as a problem
  in elasticity. The observed variations in the field are the strains
  produced by particle stresses exerted by gases in interplanetary space,
  by gases enmeshed in the field, and by the gases in the ionosphere. The
  stresses exerted by interplanetary gases are principally inward,
  resulting in the initial phase increase of the horizontal component. The
  stresses exerted by gases enmeshed in the field are principally outward,
  resulting in the main phase decrease of the horizontal component. The
  transient sudden commencement is a hydromagnetic wave phenomenon. The
  main phase is most simply explained by the shock heating of the ions
  to kev energies at 3 5 R <SUB> E </SUB> during the active phase of the
  storm. The recovery follows then from charge exchange with the ambient
  neutral hydrogen. The predicted more rapid recovery at sunspot minimum
  has been verified observationally.

Title: A Mechanism to Establish the Magnetic Storm Ring Current
Authors: Dessler, A. J.; Hanson, W. B.; Parker, E. N.
Bibcode: 1962JPSJS..17A.178D
Altcode: 1962PSJaP..17A.178D; 1962ICRC....7A.178D; 1962JPSJ...17A.178D
  No abstract at ADS

Title: Interplanetary Dynamics and Cosmic Ray Modulation
Authors: Parker, E. N.
Bibcode: 1962JPSJS..17B.563P
Altcode: 1962PSJaP..17B.563P; 1962JPSJ...17B.563P; 1962ICRC....7B.563P
  No abstract at ADS

Title: Theory of Magnetic Storms
Authors: Parker, E. N.
Bibcode: 1962JPSJS..17A.199P
Altcode: 1962ICRC....7A.199P; 1962JPSJ...17A.199P; 1962PSJaP..17A.199P
  No abstract at ADS

Title: Formation of the Geomagnetic Storm Main-Phase Ring Current
Authors: Dessler, A. J.; Hanson, W. B.; Parker, E. N.
Bibcode: 1961JGR....66.3631D
Altcode:
  It is suggested that hydromagnetic waves generated by the impact
  of solar plasma on the geomagnetic field may form shock waves in
  the magnetosphere, thus providing a mechanism for establishing
  the diamagnetic main-phase ring current. These shock waves should
  develop on the night side of the earth and heat the ambient protons
  (which constitute the normal protonosphere) to approximately
  the hydromagnetic-wave velocity (of the order of 500 km/sec). The
  transfer of hydromagnetic-wave energy to the protons stresses the
  geomagnetic field and produces the geomagnetic-storm main phase; i.e.,
  the kilovolt-energy protons form a diamagnetic current. The bombardment
  of the upper atmosphere by energetic hydrogen atoms from the decaying
  ring current and the possible change in the decay time-constant of
  the ring current through the sunspot cycle are discussed.

Title: Transresonant Electron Acceleration
Authors: Parker, E. N.
Bibcode: 1961JGR....66.2673P
Altcode:
  Helliwell and Bell have suggested synchronous acceleration of electrons
  by electromagnetic waves in the whistler range in the geomagnetic
  field. The acceleration of trapped electrons by electromagnetic
  waves is here generalized to include nonsynchronous or transresonant
  acceleration. It is shown that whistlers will scatter the electron
  velocity, by an amount inversely proportional to the square root of
  the time rate of change of the whistler frequency, during the time that
  the whistler frequency is passing over the electron gyrofrequency. Only
  electrons with initial energy above about 10<SUP>2</SUP> ev can see the
  Doppler-shifted whistler frequency at the gyrofrequency and be affected
  by this transresonant acceleration. Thermal electrons experience no
  effect. Current observation of whistlers in the outer geomagnetic field
  is too sketchy to allow a determination of transresonant acceleration
  rates, so that the relative importance, as compared, for example, with
  the strong-whistler synchronous acceleration of Helliwell and Bell,
  cannot be assessed. The importance of whistler acceleration can be
  established when the whistler frequency spectrum and recurrence rate
  are known throughout the geomagnetic field.

Title: The Distribution of Trapped Particles in a Changing Magnetic
    Field
Authors: Parker, E. N.
Bibcode: 1961JGR....66.2641P
Altcode:
  The redistribution of charged particles in the mirror field B(s, t) =
  B<SUB>0</SUB>T(t){1 + [s/a(t)]<SUP>v (t)</SUP>}is worked out for slow
  changes in T(t), a(t), and v(t). It is found that increasing T(t)
  gives a relatively greater particle density increase in the center
  of the field than deep in the mirrors s≫a(t). The mirror distance
  retracts like 1/T<SUP>1/(v+2)</SUP>. Decreasing a(t) has the opposite
  effect. Field variations constrained to preserve T(t) a<SUP>2</SUP>(t)
  and v(t) leave the form of the particle distribution unchanged,
  increasing the density everywhere by the same factor.

Title: The Stellar-Wind Regions.
Authors: Parker, E. N.
Bibcode: 1961ApJ...134...20P
Altcode:
  From the observations of the solar wind and of the M giant a Herculis
  the gross dynamical features of the stellar-wind regions associated
  with class G main-sequence and M giant stars are given for various
  interstellar environments. The supersonic wind from a class G star
  undergoes a shock transition to subsonic flow at a radial distance of
  1O-1O a u. This subsonic flow will be subject to turbulence and other
  instabilities in many cases. The wind from an M giant may extend many
  parsecs if the M-giant phase of evolution lasts as long as 1O years; the
  resultant interstellar contamination and heating are important. A rough
  calculation of the cavity formed by a stellar wind in a large-scale
  interstellar magnetic field shows that the cavity shape and dimensions
  for stationary flow depend on the pressure at infinity. As the pressure
  increases, the cavity changes from a circular cylinder of infinite
  radius, through an increasingly bulbous shape of finite radius, to
  a sphere of infinite radius with one finite cylindrical channel from
  each pole.

Title: Sudden Expansion of the Corona Following a Large Solar Flare
    and the Attendant Magnetic Field and Cosmic-Ray Effects.
Authors: Parker, E. N.
Bibcode: 1961ApJ...133.1014P
Altcode:
  We show from the hydrodynamic equations that the 4 X 106 K temperatures
  observed in the solar corona after a large solar flare can produce a
  hydrodynamic blast wave, moving out through interplanetary space with
  velocities of 1500 km/sec and densities from a few times 105/cm3 to
  105/cm3 at the orbit of earth. We suggest that it is this hydrodynamic
  explosion of the enhanced corona that is the "accelerating mechanism"
  for the "plasma clouds" or "enhanced solar corpuscular emission"
  responsible for the geomagnetic storm, the cosmic-ray decrease, the
  low4atitude aurorae, etc, observed at earth a day or two following
  large solar flares on the visible hemisphere of the sun. We compute the
  interplanetary magnetic field in the blast wave, assuming an initial
  quiet-day solar wind of a few hundred km/sec ahead of the wave. The
  spiral field of the quiet-day wind is sheared by the blast wave, and its
  density, of the order of 2 X 10- gauss at the orbit of earth, may be
  increased to 5 X 10- gauss or more for a period of several hours. The
  effect of the outward-sweeping magnetic shear in the blast wave is
  to decrease the cosmic-ray intensity, occasionally perhaps by as much
  as 40 per cent, in the inner solar system behind the blast wave. The
  onset of the decrease has a characteristic time of several hours,
  and the relaxation many hours or days. The energy dependence of the
  decrease may go inversely with particle rigidity, or it may be flatter,
  depending on the details of the magnetic configuration in and around
  the blast wave. Thus the cosmic-ray decrease produced by the blast
  wave is identical with the Forbush-type cosmic-ray decrease observed
  in association with "enhanced solar corpuscular radiation." Thus,
  besides producing the observed 1500 km/sec ejection of matter from the
  sun responsible for the geomagnetic storm, the hydrodynamic expansion
  of the enhanced corona produces the observed Forbush decrease. We
  suggest, therefore, that the simple dynamical model of the enhanced
  corona developed in this paper is not unlike what actually occurs
  following a large solar flare.

Title: Effect of Hydromagnetic Waves in a Dipole Field on the
    Longitudinal Invariant
Authors: Parker, E. N.
Bibcode: 1961JGR....66..693P
Altcode:
  Hydromagnetic wave violation of the longitudinal invariant of a particle
  trapped in a mirror magnetic field is investigated quantitatively. It
  is shown that the passage of hydromagnetic waves across the region
  of mirroring leads to a diffusion of the individual-particle mirror
  points. If the relative wave amplitude ΔB/B is maintained throughout
  the mirror field, particles released in the field will soon diffuse
  out through the mirror and be lost. Application to thermonuclear
  devices is obvious. Confining our attention principally to the charged
  particles trapped in the geomagnetic field, it is shown that high-energy
  (10<SUP>5</SUP>-ev) electrons in the outer Van Allen radiation zone
  are caused to diffuse along the lines of force with a characteristic
  time of 4 months by hydromagnetic waves of 1 cps and an amplitude of
  10<SUP>-4</SUP> gauss. Hydromagnetic diffusion appears to be more
  important than collisions in determining the electron lifetime and
  distribution in the outer Van Allen radiation zone. Different wave
  distributions along the lines of force can give radically different
  particle distributions. It is shown that, if the hydromagnetic
  disturbances extend throughout the geomagnetic field, then, rather than
  yielding particle acceleration, they result in a net loss of particle
  energy. But if we assume a region of hydromagnetic disturbance localized
  inside the geomagnetic field, limited particle acceleration may result.

Title: The Interplanetary Gas and Magnetic Fields
Authors: Parker, E. N.
Bibcode: 1961sis..book..229P
Altcode:
  No abstract at ADS

Title: The Solar Wind
Authors: Parker, E. N.
Bibcode: 1961spas.book..157P
Altcode:
  No abstract at ADS

Title: The Hydrodynamic Theory of Solar Corpuscular Radiation and
    Stellar Winds.
Authors: Parker, E. N.
Bibcode: 1960ApJ...132..821P
Altcode:
  We show from the conventional application of the static barometric law
  to the density of the solar corona, observed out to 20 RO at sunspot
  minimum, that the corona would be so hot at 20 RO that it could
  not be static but must expand. Thus one cannot correctly deduce the
  temperature in the outer corona from the density distribution by using
  the static barometric law. Allowing for the possibility of expansion,
  we find that the solution of the stationary, spherically symmetric,
  hydrodynamic equation for a uniform coronal temperature of 1.22 X 106
  0K fits the observed coronal density predsely out to 14 R O,indicating
  an expansion velocity of the order of 300 km/sec at large radial
  distances. We conclude that at sunspot minimum the coronal temperature
  is 1.22 X 106 0K. We carry out an extensive investigation of the
  singular mathematical properties of the solutions of the stationary,
  spherically symmetric, non-linear hydrodynamic equation for the
  polytrope law P a N0. We show that there exist continuous solutions 4,
  [(4,o) , a, X; which go from low velocity in a strong gravitational
  field at the base of the corona out to infinity with the necessary
  boundary condition that p( ) = 0. These solutions yield supersonic
  velocities of expansion. In terms of the polytrope index, a, and the
  gravitational parameter, X GMOM/ROk T0, we show that these solutions
  exist for a strong gravitational field (X »1), provided only that a
  &lt; T3 and X &lt; 2a/(a - 1). Since observations of the solar corona
  show that these conditions are satisfied, we demonstrate formally the
  expansive nature of the solar corona. The mathematical theory allows
  us to work out the upper and lower bounds on the velocity of expansion
  of the solar corona-the solar wind-into interplanetary space. We find
  that at solar minimum the velocity of expansion may be only 300 km/sec,
  with densities as low as 20/cm2 at the orbit of earth. The quiet-day
  solar wind during the years of solar activity is evidently more than
  500 km/sec. The solar wind is obviously what has heretofore been termed
  the ccsolar corpuscular radiation," to which quiet-day velocities and
  densities of 500 km/sec and 102/cm3 have been assigned on the basis
  of a number of independent observational analyses. We show that we
  expect at least all main-sequence stars later than class F to possess
  stellar winds, in analogy with the solar wind, so that the phenomenon
  is of widespread importance in the mass balance of the Galaxy, as well
  as in the early evolution of most stars. In the appendix we give an
  outline of the theory of hydromagnetic heating of the solar corona,
  pointing out that the ion thermal velocity in a stellar atmosphere, in
  which hydromagnetic heating is dominant, should be of the same order
  as the bydromagnetic wave velocity. This prediction is in agreement
  with the observed solar coronal temperatures.

Title: Geomagnetic Fluctuations and the Form of the Outer Zone of
    the Van Allen Radiation Belt
Authors: Parker, E. N.
Bibcode: 1960JGR....65.3117P
Altcode:
  It is demonstrated by formal calculation that the large-scale
  geomagnetic fluctuations observed at ground stations result in a rapid
  and somewhat remarkable kind of diffusion of the electrons in the
  outer zone of the Van Allen radiation belt. An initial thin ring of
  electrons will give an immediate finite particle flux at infinity, at
  the same time that the group of the particles remaining moves radially
  inward as a `wave'. We predict a decline of particle counting rate
  beyond about 4 earth radii of the order of 1/r<SUP>β</SUP>, where
  β≅12 to 16, depending upon the kind of counter, in agreement with
  the many observations.

Title: Geomagnetic Storm Sudden-Commencement Rise Times
Authors: Dessler, A. J.; Francis, W. E.; Parker, E. N.
Bibcode: 1960JGR....65.2715D
Altcode:
  Adopting the view that the sudden commencement of a geomagnetic
  storm (SC) is the result of the impact on the geomagnetic field of an
  abrupt solar-plasma front, the form of the SC observed on the surface
  of the earth is investigated. A model is constructed to represent
  the shape of the geomagnetic field boundary as perturbed by the
  solar plasma. Calculations (carried out in the equatorial plane for
  simplicity) show that, regardless of how abrupt may be the impact
  of a solar-plasma front on the geomagnetic field, the variation in
  hydromagnetic transit times from different positions on the boundary,
  down to a point on the surface of the earth, yields SC rise times of
  several minutes at ground level. These times are in agreement with
  the observed SC rise times.

Title: The Hydrodynamic Treatment of the Expanding Solar Corona.
Authors: Parker, E. N.
Bibcode: 1960ApJ...132..175P
Altcode:
  It has been argued elsewhere that our earlier hydrodynamic treatment
  of the solar corona, which predicted a steady 500-km/sec expansion,
  is incorrect and that the appropriate treatment of the mass loss to
  the solar corona is with the classical evaporation theory of Jeans
  et at. In the first part of this paper we investigate the singular
  properties of the solutions of the hydrodynamic equations and show
  that the only stationary solution appropriate to the solar corona
  is the critical solution, which passes straight across the critical
  point and yields supersonic (500-km/sec) expansion at infinity. In
  the second part of the paper we show that the evaporative solutions
  are incompatible with the hydrodynamic equation and hence incompatible
  with the Boltzmann equation.

Title: Statement of Agreement regarding the Ring-Current Effect
Authors: Hines, C. O.; Parker, E. N.
Bibcode: 1960JGR....65.1299H
Altcode:
  In an earlier communication [Hines and Parker, 1958], we recorded
  discrepant views regarding the possible magnetic effects at the ground
  caused by a hypothetical ring current in the earth's exosphere. This
  followed upon earlier statements by Parker [1956, 1958a and b] to the
  effect that only an increase of geomagnetic field could be produced
  in a reasonably short time by such a current, as a consequence of
  exospheric shielding, and conflicting statements by Hines [1957] and
  Hines and Storey [1958] to the effect that geomagnetic field changes
  of either sense could be propagated rapidly through the exosphere by
  hydromagnetic waves. In view of the interest that this controversy
  appears to have raised, and because of the basic importance of the
  consequences in geomagnetic storm theory, we wish now to record a
  reconciliation of views, to the effect that circulating charge high in
  the exosphere can indeed be associated with a decrease of geomagnetic
  field at ground level in a reasonably short time and, therefore, may
  indeed be responsible for the main phase of a geomagnetic storm. In
  order to clarify the basic features of the controversy most readily,
  the original discrepant views will be restated briefly in application to
  very extreme models where each in turn undoubtedly applies. It should
  be noted, however, that each view can in turn be justified for other
  models which bear a much closer resemblance to the circumstances of
  nature, and the separate conclusions were originally formulated with
  these other models in mind.

Title: Extension of the Solar Corona into Interplanetary Space
Authors: Parker, Eugene
Bibcode: 1960exsp.conf...28P
Altcode:
  No abstract at ADS

Title: Extension of the Solar Corona into Interplanetary Space
Authors: Parker, Eugene
Bibcode: 1959JGR....64.1675P
Altcode:
  I shall first write down a number of observational facts, and then in
  another column compare them with the results of the theoretical program
  we have been carrying out at Chicago over the past few years. The
  purpose of this comparison will be to suggest experiments, some of
  which are already in progress, and which will perhaps resolve a few
  of the difficulties in our present knowledge of the dynamics of the
  interplanetary medium. I shall start with the sun, since we believe,
  as Gold and others have pointed out, that it is the source of energy for
  all phenomena observed in the earth, in particular magnetic storms and
  auroras, and the source of energy for all the churning that apparently
  occurs in interplanetary space. Let me list a few basic facts about
  the sun that seem most pertinent to the problem.

Title: Plasma Dynamical Determination of Shock Thickness in an
    Ionized Gas (a Correction).
Authors: Parker, E. N.
Bibcode: 1959ApJ...129..860P
Altcode:
  No abstract at ADS

Title: Plasma Dynamic Determination of Shock Thickness in an
    Ionized Gas.
Authors: Parker, E. N.
Bibcode: 1959ApJ...129..217P
Altcode:
  It is shown that the principal interaction in a shock front in a
  tenuous ionized gas is a plasma interaction in which the ions transfer
  their translational energy to the plasma oscillations. The effect
  is, of course, of interest in auroral theories and in solar radio
  noise. It turns out to be the dominant effect in determining shock
  thicknesses nearly everywhere that the gas density is less than the
  solar photospheric value of 1016 atoms/cm3. We estimate that shock
  thicknesses in interstellar H ii regions and in interplanetary space
  will be 1 km or less, even though the mean free paths may be 108 km
  or more and the ion Larmor radius 100 km.

Title: Inadequacy of Ring-Current Theory for the Main Phase of a
    Geomagnetic Storm
Authors: Parker, E. N.
Bibcode: 1958JGR....63..683P
Altcode:
  It is demonstrated that there is apparently not enough dissipation to
  allow significant diffusion, during a magnetic storm, of the magnetic
  fields in the vicinity of the earth. It is then demonstrated that
  a ring-current field can only increase the horizontal component of
  the geomagnetic field, and so cannot account for the main phase of a
  geomagnetic storm. Thus, other storm mechanisms must be sought.

Title: Statement of Differences Regarding the Ring-Current Effect
Authors: Hines, C. O.; Parker, E. N.
Bibcode: 1958JGR....63..691H
Altcode:
  The two preceding articles have expressed different views concerning
  the possible effects of ring currents, and have supported those views
  at some length by quite distinct analyses. It is probable that the
  essential points of difference which still remain require clarification,
  and the purpose of this note is to provide that clarification. The
  statements made here are based on views expressed in a lengthy private
  correspondence between the present authors, who, unfortunately, were
  unable to reconcile their differences. In Parker's view, a magnetic
  field such as that pictured in Figure 1 would be distorted for an
  extremely long time into the form given in Figure 2, following the
  introduction of a line-current source such as that indicated. The
  shaded areas are intended to represent the region filled by a highly
  conducting fluid, before and after the establishment of the current;
  the unshaded areas represent the space swept clear of fluid by the
  newly created ring-current field. This picture is based on the fact
  that the equations describing electromagnetic effects in a conducting
  fluid can be written in the usual hydromagnetic form ? which implies
  that the lines of force and the fluid move exactly together. From this,
  Parker deduces that the field of a newly created ring current cannot
  immediately penetrate the surrounding gas, and so will push back the
  gas and the pre-existent field lines, as in Figure 2.

Title: Suprathermal Particles. III. Electrons
Authors: Parker, E. N.
Bibcode: 1958PhRv..112.1429P
Altcode:
  Certain phenomena in nature, such as the 50- to 100-kev electrons of
  the aurora, suggest that there are plasma-dynamical processes which
  can quickly transfer the translational energy of the ions in a plasma
  stream to the electrons (some 20 kev/ion for a 2000-km/sec solar
  wind). It is shown that two interpenetrating streams of noncolliding
  and initially neutral plasma can achieve this energy transfer with a
  characteristic time comparable to (Mm)<SUP>12</SUP> times the plasma
  period. The process is closely analogous to the excitation of plasma
  oscillations by two interpenetrating electron streams, but of course
  proceeds to much greater electron energies because the ion components
  of the streams carry so much more kinetic energy than do the electron
  components. Hence, besides the auroral electrons, it is probably
  responsible for solar radio emission, rather than the electron streams
  implied in current theories. Further, the process is probably the
  dominant interaction in shock fronts, particularly in astrophysical
  cases where neither direct collisions nor the existing weak magnetic
  fields can give sharp fronts. The characteristic thickness of a shock
  front in the solar wind is of the order of 10<SUP>4</SUP> cm due to
  the above plasma excitation whereas the Larmor radius of the ions,
  which would otherwise determine the shock thickness in the absence of
  collisions, is 100 km or more.

Title: Suprathermal Particle Generation in the Solar Corona.
Authors: Parker, E. N.
Bibcode: 1958ApJ...128..677P
Altcode:
  It is shown that hydromagnetic waves propagating outward through the
  solar corona will convert all but a small portion of their energy into
  suprathermal particles It is suggested that this is the source, of the
  3 X 1028 ergs/sec necessary to maintain the 2 X 108 0K solar corona
  with its continued expansion into the solar wind The temperature of
  the solar corona will then correspond to an ion thermal velocity of
  the same order of magnitude as the hydromagnetic wave velocity.

Title: Dynamics of the Interplanetary Gas and Magnetic Fields.
Authors: Parker, E. N.
Bibcode: 1958ApJ...128..664P
Altcode:
  We consider the dynamical consequences of Biermann's suggestion that
  gas is often streaming outward in all directions from the sun with
  velocities of the order of 500-1500 km/sec. These velocities of 500
  km/sec and more and the interplanetary densities of 500 ions/cm3
  (1014 gm/sec mass loss from the sun) follow from the hydrodynamic
  equations for a 3 X 1060 K solar corona. It is suggested that the
  outward-streaming gas draws out the lines of force of the solar magnetic
  fields so that near the sun the field is very nearly in a radial
  direction. Plasma instabilities are expected to result in the thick
  shell of disordered field (10- gauss) inclosing the inner solar system,
  whose presence has already been inferred from cosmic-ray observations.

Title: Suprathermal Particles
Authors: Parker, E. N.; Tidman, D. A.
Bibcode: 1958PhRv..111.1206P
Altcode:
  The production of suprathermal particles in agitated plasmas bearing
  magnetic fields is discussed. This is done by setting up a Fokker-Planck
  equation to describe the phenomenon. The role of such particles in
  astrophysics and in the problem of the production of thermonuclear
  power is considered.

Title: Gross Dynamics of the Interstellar Medium
Authors: Parker, E. N.
Bibcode: 1958RvMP...30..955P
Altcode: 1958IAUS....8..955P
  No abstract at ADS

Title: Cosmic-Ray Modulation by Solar Wind
Authors: Parker, E. N.
Bibcode: 1958PhRv..110.1445P
Altcode:
  It is shown that the hydrodynamic outflow of gas from the sun observed
  by Biermann results in a reduction of the cosmic-ray intensity in the
  inner solar system during the years of solar activity. The computed
  cosmic-ray energy spectrum so closely resembles the observed spectrum
  at earth that we suggest the outflow of gas to be the explanation for
  the 11-year variation of the cosmic-ray intensity. It is also suggested
  that perhaps the Forbush-type decrease, which is a local geocentric
  phenomenon, is the result of disordering of the outer geomagnetic
  field by the outflowing gas from the sun.

Title: Electrical Conductivity in the Geomagnetic Storm Effect
Authors: Parker, E. N.
Bibcode: 1958JGR....63..437P
Altcode:
  Hines<SUP>1</SUP> has recently argued that it is possible for
  the magnetic field of a ring current to penetrate rapidly through
  the electrically conducting gas surrounding the earth because the
  geomagnetic field greatly reduces the conductivity perpendicular
  to the lines of force. In this way, he argues that a ring current
  can very quickly cancel (dissipate) part of the geomagnetic field
  at the surface of the earth to yield the main phase of a geomagnetic
  storm. Now it was first pointed out by Schlüter,<SUP>2</SUP> and has
  since been discussed by Bungey,<SUP>3</SUP> and by Cowling,<SUP>4</SUP>
  that the decay or dissipation of a magnetic field is not enhanced by
  the reduction of conductivity perpendicular to B. As Cowling puts it,
  one is justified in discussing the conductivity only if at the same
  time he considers the effective electric field.

Title: Interaction of the Solar Wind with the Geomagnetic Field
Authors: Parker, E. N.
Bibcode: 1958PhFl....1..171P
Altcode:
  The dynamical properties of the solar wind blowing past the geomagnetic
  field are investigated by considering the effective viscosity and the
  resulting transition layer thickness. The collision of ions in the solar
  wind produces a negligible viscosity in the flow past the geomagnetic
  field, but such an inviscid flow is shown to be unstable. The resulting
  disordered interface between the field and the wind yields Fermi
  acceleration of ions and consequently a not insignificant effective
  viscosity. The Fermi acceleration results in suprathermal ions which
  may have an energy spectrum like that observed for primary auroral
  protons. <P />The auroral zones and the agitated nature of the polar
  geomagnetic field are shown to follow from the depth of penetration of
  the solar wind into the geomagnetic field. The injection of gas into the
  geomagnetic field is studied. The effect at Earth of the distortion of
  the outer boundary of the geomagnetic field is computed; no matter how
  unevenly and anisotropically the outer field is distorted, the effect at
  Earth is a nearly uniform perturbation field which is closely parallel
  to the geomagnetic axis. Pushing in on the outer field increases the
  horizontal component at Earth, and pulling out decreases it; the total
  increase of the horizontal component is the algebraic sum of all the
  pushing and pulling. The simultaneous world-wide onset and the main
  phase of a geomagnetic storm follow. <P />The common tendency of large
  and/or violent bodies of plasma to produce suprathermal particles is
  noted and suggested to be a general dynamical property.

Title: Dynamical Instability in an Anisotropic Ionized Gas of
    Low Density
Authors: Parker, E. N.
Bibcode: 1958PhRv..109.1874P
Altcode:
  It is shown that when the thermal motions of a tenuous ionized gas are
  sufficiently anisotropic, the gas, and the initially uniform magnetic
  field which the gas is assumed to contain, become unstable. One mode
  of instability occurs when the gas pressure is greater parallel to
  the field than perpendicular, and another mode when the pressure
  is greater perpendicular than parallel. It is suggested that such
  instabilities may be of astrophysical interest, particularly with
  regard to the configuration of the solar dipole field as it is drawn
  out into interplanetary space by ionized gas from the sun.

Title: Origin and Dynamics of Cosmic Rays
Authors: Parker, E. N.
Bibcode: 1958PhRv..109.1328P
Altcode:
  As a consequence of our inability to observe directly the origin of
  a cosmic-ray particle, we begin the development with a discussion of
  the limitations within which we can construct a cosmic-ray accelerator
  mechanism. We find that we are allowed only the betatron effect and
  the Fermi mechanism. We review some of the many variations of these
  mechanisms which are to be found in the literature. Then it is shown
  that trains of oppositely moving hydromagnetic waves of large amplitude
  and with sharp crests can accomplish large and continued particle
  accelerations which are adequate to maintain the observed galactic
  cosmic-ray field. The large acceleration arises as a consequence
  of the simple fact that each wave tends to sweep up the cosmic-ray
  particles before it, so that head-on collisions of particles with
  waves are much more common than overtaking collisions. It is pointed
  out that the sharp crests of the waves are a natural consequence of
  the observed supersonic mass motions. Therefore, the acceleration by
  oppositely moving waves does not depend upon any special wave form, and
  we suggest that it is the naturally occuring acceleration process. By
  treating the cosmic rays as a gas with relativistic thermal motions,
  it is shown that the cosmic-ray gas is effectively coupled to the
  motions of the ordinary matter both parallel and perpendicular to the
  magnetic field. Thus the effective speed of sound must be computed in
  the composite cosmic-ray and ordinary gas. It is noted that with this
  composite speed of sound the irregular mass motions in the galactic
  disk and halo are approximately Mach one. It is suggested that this
  represents a general dynamic balance to be found in all sufficiently
  active regions of space, and explains how it is that we often observe
  prolonged mass motions in the galaxy and in stellar atmospheres which
  would otherwise be computed to be highly supersonic and dissipative. The
  dynamic balance comes about from the fact that increased cosmic-ray
  density would reduce the effective Mach number below one, allowing
  the sharp crests of the hydromagnetic waves to degenerate, and thereby
  halting the production of comsic-ray particles.

Title: On the Variations of the Primary Cosmic Ray Intensity
Authors: Parker, E. N.
Bibcode: 1958IAUS....6..420P
Altcode:
  No abstract at ADS

Title: Sweet's Mechanism for Merging Magnetic Fields in Conducting
    Fluids
Authors: Parker, E. N.
Bibcode: 1957JGR....62..509P
Altcode:
  Sweet's mechanism for the merging of two oppositely directed
  magnetic fields in a highly conducting fluid is investigated in a
  semi-quantitative manner. It is shown that two oppositely directed
  sunspot fields with scales of 10<SUP>4</SUP> km could be merged by
  Sweet's mechanism, if shoved firmly together, in about two weeks; their
  normal interdiffusion time would be of the order of 600 years. It is
  suggested that Sweet's mechanism may be of considerable astrophysical
  importance: It gives a means of altering quickly the configuration of
  magnetic fields in ionized gases, allowing a stable field to go over
  into an unstable configuration, subsequently converting much of the
  magnetic energy into kinetic energy of the fluid.

Title: Acceleration of Cosmic Rays in Solar Flares
Authors: Parker, E. N.
Bibcode: 1957PhRv..107..830P
Altcode:
  It is shown that the white-light cosmic-ray solar flare of February
  23, 1956 expended of the order of 2×10<SUP>32</SUP> ergs of energy,
  or 10<SUP>4</SUP> ergs/cm<SUP>3</SUP>. The energy apparently came from
  a 500-gauss force-free magnetic field initially occupying the site of
  the flare. It is shown that the 500-gauss field, besides supplying
  the flare energy, will produce fluid motions of sufficient velocity
  to accelerate ions from thermal to relativistic energies by Fermi's
  mechanism in about 2 minutes. The theoretical energy spectrum of the
  model is in agreement with the observed spectrum. About one percent
  of the total flare energy is converted to relativistic particles and
  the remainder is dissipated through thermal processes to produce the
  observed optical radiation.

Title: The Gross Dynamics of a Hydromagnetic Gas Cloud.
Authors: Parker, Eugene N.
Bibcode: 1957ApJS....3...51P
Altcode:
  The tensor virial equations are applied to the dynamics of magnetic gas
  clouds in which self-gravitation is negligible, such as are presumed to
  be ejected from the sun into interplanetary space. To avoid the immense
  mathematical difficulties of a general treatment, we constrain the cloud
  to homogeneous, though not necessarily isotropic, dilatation. It is
  shown that, in the absence of an external magnetic - field surrounding
  the cloud, no static equilibrium is possible without non-vanishing
  external gas pressure. The unsymmetric expansion of a cloud along
  one axis is considered. In the presence of an external large-scale
  magnetic field surrounding the cloud, it is necessary, in order that
  we may compute the external field, to pad- the cloud surface so that
  the over-all shape will be ellipsoidal. Cloud equilibrium conditions
  are given in the presence of the external fiel 1. The force exerted on
  a cloud by a gradient in the external field is given; it is shown that
  a cloud expelled, like a melon seed, from a large-scale field may have
  a velocity as great the speed of sound or the Alfve'n wave velocity,
  whichever is greater. It is shown that a field-free cloud of gas be
  contained between constrictions in a large-scale field; but we do not
  expect to find permanent field-free clouds in nature because such a
  cloud will repeatedly split lengthwise or otherwise decrease one of its
  limit, until the field-free gas diffuses into the external field. -
  It is pointed out that, except -in special cases where the cloud is
  held together by constrictions in an external field, the existence of
  a static equilibrium requires that the lines of force of the internal
  cloud field be tangled.

Title: The Solar Hydromagnetic Dynamo
Authors: Parker, E. N.
Bibcode: 1957PNAS...43....8P
Altcode:
  No abstract at ADS

Title: On the Geomagnetic Storm Effect
Authors: Parker, E. N.
Bibcode: 1956JGR....61..625P
Altcode:
  The high electrical conductivity of the region surrounding Earth,
  inferred from the observations of atmospheric whistlers and the
  zodiacal light, requires abandoning the customary models for producing
  a geomagnetic storm field with impressed current system. It becomes
  necessary to adopt a purely hydromagnetic approach wherein one
  focuses his attention only on the magnetic lines of force of the
  geomagnetic field and their displacement with the conducting gas
  surrounding Earth. From the hydromagnetic point of view, a decrease
  of the horizontal component is brought about by lifting the lines of
  force in the region above the observer. It is suggested that heating
  in the upper atmosphere may produce the necessary lifting; this model,
  along with another, is developed quantitatively to show that lifting
  the lines of force a distance of only 5 km will produce a decrease in
  the horizontal component of 0.2 per cent at the equator.

Title: Solar Cosmic Rays of February, 1956 and Their Propagation
    through Interplanetary Space
Authors: Meyer, P.; Parker, E. N.; Simpson, J. A.
Bibcode: 1956PhRv..104..768M
Altcode:
  The data from six neutron-intensity monitors distributed over a wide
  range of geomagnetic latitudes have been used to study the large and
  temporary increase of cosmic-ray intensity which occurred on February
  23, 1956, in association with a solar flare. During the period of
  enhanced intensity a balloon-borne neutron detector measured the
  absorption mean free path and intensity of the flare particles at
  high altitudes. From these experiments the primary particle intensity
  spectrum as a function of particle rigidity, over the range &lt;2
  to&gt; 15-30 Bv rigidity, has been deduced for different times during
  the period of enhanced intensity. It is shown that the region between
  the sun and the earth should be free of magnetic fields greater than
  ~10<SUP>-6</SUP> gauss and that the incoming radiation was practically
  isotropic for more than 16 hours following maximum flare particle
  intensity. The decline of particle intensity as a function of time t
  depends upon the power law t<SUP>-32</SUP>, except for high-energy
  particles and late times, where the time dependence approaches an
  exponential. The experiments lead to a model for the inner solar system
  which requires a field-free cavity of radius greater than the sun-earth
  distance enclosed by a continuous barrier region of irregular magnetic
  fields [B(rms)~10<SUP>-5</SUP> gauss] through which the cosmic-ray
  particles must diffuse to reach interstellar space. This barrier
  is also invoked to scatter flare particles back into the field-free
  cavity and to determine the rate of declining intensity observed at the
  earth. The diffusion mechanism is strongly supported by the fact that
  the time dependence t<SUP>-32</SUP> represents a special solution of
  the diffusion equation under initial and boundary conditions required
  by experimental evidence. The coefficient of diffusion, the magnitude
  of the magnetic field regions, the dimensions of the barrier and cavity,
  and the total kinetic energy of the high-energy solar injected particles
  have been estimated for this model. Recent studies of interplanetary
  space indicate that the conditions suggested by the experiments may
  be established from time to time in the solar system. The extension of
  the model to the explanation of earlier cosmic-ray flare observations
  appears to be satisfactory. The solar flare event was superposed
  by chance upon a large but typical intensity decrease of nonsolar
  cosmic rays which began several days prior to February 23. Hence,
  the flare particles have been used as probes to explore the intensity
  modulation mechanism responsible for this decrease of background
  cosmic-ray intensity.

Title: Modulation of Primary Cosmic-Ray Intensity
Authors: Parker, Eugene N.
Bibcode: 1956PhRv..103.1518P
Altcode:
  It is assumed that the cosmic-ray particles observed at the earth
  are of galactic origin, except for the occasional bursts from
  solar flares. With this interpretation the 11-year variation of the
  cosmic-ray intensity and the Forbush decreases represent depressions
  of the steady galactic intensity. The observed rigidity dependence
  of the depression indicates that magnetic fields are responsible. A
  quantitative investigation of the possible motion and configuration of
  magnetic fields capable of producing the observed effects is carried
  out. It is shown that, within the limitations imposed by what we think
  we know today of the galactic magnetic field, of solar activity, and
  of interplanetary fields, serious difficulties are encountered by any
  mechanism, such as Morrison's interplanetary cloud model, modulating
  the galactic cosmic-ray intensity throughout the solar system. It is
  proposed that the modulation of the intensity is produced locally,
  within a few earth's radii, by interplanetary magnetic gas clouds
  captured by the terrestrial gravitational field. Such a model seems
  to produce the observed effects on the basis of the known facts about
  solar activity. The most straightforward test of this geocentric
  model, independent of inferences from cosmic-ray effects, is the
  question of whether the absorption of the captured magnetic hydrogen
  gas can be detected as a narrow line in the center of the broad solar
  L<SUB>α</SUB> emission line.

Title: Diffusion and Severing of Magnetic Lines of Force.
Authors: Parker, E. N.; Krook, M.
Bibcode: 1956ApJ...124..214P
Altcode:
  The general asymptotic form for the magnetic field in a diffusing flux
  tube is developed and applied to the problem of severing magnetic lines
  of force in a medium with finite electrical conductivity Calculations
  of the details of the severing and reconnection of lines of force are
  given for the formation of an idealized free meridional magnetic ring
  in a hydromagnetic dynamo, for the merging of idealized neighboring
  rings, and for the straightening of the lines in a twisted tube, in
  order to illustrate the general qualitative features of these processes
  as they would presumably occur in the core of the earth. The problem
  of two nearly intersecting slender flux tubes is considered in order
  to demonstrate how the lines of force of the lesser tube are diverted
  into the denser tube.

Title: Hydromagnetic and Plasma Problems
Authors: Parker, Eugene N.
Bibcode: 1956SCoA....1...59P
Altcode:
  No abstract at ADS

Title: Hydromagnetic Dynamo Models.
Authors: Parker, Eugene N.
Bibcode: 1955ApJ...122..293P
Altcode:
  The purpose of this paper is to investigate the steady-state
  amplification of magnetic fields in a fluid It is shown that a rotating
  sphere of conducting fluid can regenerate a dipole magnetic field. It is
  sufficient for the angular velocity of rotation to vary with distance
  from the axis of rotation and for cyclonic fluid motions to be present
  The nonuniform rotation generates a toroidal field from the dipole
  field; the cyclones generate, from the toroidal field, loops of flux
  in the meridional plane which coalesce to amplify the dipole field The
  rotating sphere is discussed in relation to the liquid core of the earth
  and the geomagnetic dipole field. If, instead of a rotating sphere, one
  has a prismatic volume of fluid, it is possible to construct migratory
  dynamo waves The dynamo waves are discussed in relation to the solar
  convective zone; it is shown that such waves can account for many of
  the principal features of the observed solar magnetic activity

Title: Hydromagnetic Waves and the Acceleration of Cosmic Rays
Authors: Parker, Eugene N.
Bibcode: 1955PhRv...99..241P
Altcode:
  The large amounts of energy necessary for the acceleration of
  cosmic rays throughout the galaxy introduces a serious transport
  problem. The hydrodynamic and hydromagnetic equations are investigated
  from the viewpoint of energy propagation. It is shown that, with the
  galactic model of Fermi and Chandrasekhar, the observed motions of the
  interstellar gas reduce to hydromagnetic waves, which are, as it turns
  out, the most effective means of energy transport. A consideration of
  the interaction of charged particles with hydromagnetic waves shows that
  it is the fluid velocity, and not the wave velocity, that is responsible
  for the acceleration of cosmic rays by Fermi's mechanism. We calculate
  the the dissipation of hydromagnetic waves in the interstellar medium,
  and the variation of amplitude and wavelength of such waves with changes
  in density and large-scale field intensity. It is then shown that the
  galaxy is no more than one percent efficient in the acceleration of
  cosmic rays because of the tremendous viscous losses in the interstellar
  medium, and that there is no hydromagnetic mechanism that can convert
  the observed large-scale low-velocity fluctuations in the interstellar
  medium to the required small-scale high-velocity motions.

Title: The Formation of Sunspots from the Solar Toroidal Field.
Authors: Parker, Eugene N.
Bibcode: 1955ApJ...121..491P
Altcode:
  It is shown that a horizontal magnetic flux tube in an electrically
  conducting atmosphere is buoyant and will tend to rise. This magnetic
  buoyancy is large enough to bring an occasional strand of flux from
  the general solar toroidal field up into the photosphere, if we assume
  general field densities of a few hundred gauss farther down. Identifying
  the intersection of such ropes with the photosphere as the source
  of sunspots, we may deduce several general characteristics of the
  spots, e.g., east-west orientation, bipolarity, appearance only in low
  latitudes, migration, reversal of polarity, etc. The linearized static
  equilibrium equations for a flux tube are developed. With a cooling
  mechanism, such as that suggested by Biermann (1941), we find from the
  equilibrium equations that a sunspot group should consist of a diffuse
  flux tube of 10-100 gauss and 10 km extent in the photosphere, forming
  eventually a number of cool intense cores of several thousand gauss.

Title: Instability of Thermal Fields.
Authors: Parker, Eugene N.
Bibcode: 1953ApJ...117..431P
Altcode:
  The field equation for the kinetic temperature, Te, is considered in the
  case of a gas composed of hydrogen-like atoms. If the atoms are largely
  ionized and free-free emission does not predominate, the thermal field
  is unstable unless stabilized by a strongly temperature-dependent supply
  of energy. The possibility of interpreting much of the thermal activity
  in the solar atmosphere as due to such instability is discussed.

Title: On the instability of gaseous media.
Authors: Parker, Eugene N.
Bibcode: 1953AJ.....58Q..46P
Altcode:
  Introducing the assumption that all large scale astrophysical
  structures, e.g., gas clouds, galaxies, etc. have formed by collapse
  of regions of an initially more homogeneous distribution of matter
  according to Jeans' gravitational instability criterion, it is possible
  to work backwards from existing conditions to the initial conditions. It
  is found that gravitational instability produces a collapse in which
  the scale of the final structure is approximately one-sixth of its
  original dimensions. This agrees with observations of the interstellar
  gas clouds which show that the clouds are separated by approximately
  twice the diameter of their extremities. Given the relative velocity of
  neighboring clouds, it is possible from the diameter of the clouds to
  determine the average density of the interstellar medium. The relative
  velocity 3 km/sec gives roughly 10 hydrogen atoms per cm1. This agrees
  with the average density computed by smearing out the estimated mass
  of the galaxy over the estimated dimensions of the galaxy. The collapse
  time in such a medium is of the order of I0~ years. On the other hand,
  galaxies are separated by distances of the order of 100 or more times
  their diameters, implying that they have separated greatly since
  their formation. Observations imply masses of the order of 1011 Mo
  and internal velocities 300 km/sec for the brighter galaxies. From
  these is predicted a relative velocity 50 km/sec for galaxies not in
  clusters. The observed motions and dimensions of both spheroidal and
  spiral galaxies yield an initial mean density of the order of 5 X 10-26
  gm/cm3 at the time the collapse of the primordial homogeneous medium
  began. That both types give the same initial density suggests that
  regions not occupied by relatively active eddies have collapsed over
  smaller dimensions to form spheroidal galaxies, i.e., galaxies of low
  mass, whereas active regions, if they collapse at all, form the more
  massive galaxies. Finally, the collapse time for forming a galaxy is
  found to be of the order of 3 X 108 years. Department of Mathematics
  and Astronomy, University of Utah, Salt Lake City, Utah.

Title: The Interstellar Structures. I. Gas Clouds.
Authors: Parker, Eugene N.
Bibcode: 1953ApJ...117..169P
Altcode:
  In an effort to arrive at a dynamical model for the interstellar
  medium, its mechanical properties are discussed. Using a polytrope
  relation between the temperature and density within a gas cloud, the
  mechanical and then the statistical properties of an idealized model of
  the interstellar clouds are developed. One finds that the collision rate
  of clouds, computed in an elementary fashion from their diameters and
  random translational velocities, leads to several difficulties. First,
  the very inelastic nature of head-on collisions would rapidly reduce
  the translational velocities, and it would be difficult to explain the
  observed radial velocities. Second, there would be a strong tendency
  toward statistical equilibrium of the internal state of the clouds. The
  equilibrium is investigated, and the cloud is found to be either in
  a collapsed condition or completely dispersed, again contrary to
  observation. Ordering of the translational velocities is proposed
  as one means of circumventing these difficulties. In any case, the
  tendency of clouds to collapse, possibly to form clusters of stars,
  is shown to be intrinsic in their nature.

Title: An analytical investigation of turbulence and acoustics in
    the solar ionization zone.
Authors: Parker, Eugene N.
Bibcode: 1952AJ.....57Q..22P
Altcode:
  An investigation of the turbulence field to be expected in the solar
  ionization zone requires an extension of the existing turbulence
  theories to cover the case of an inhomogeneous field where convective
  forces are producing the turbulence. Heisenberg's development of
  isotropfc homogeneous turbulence was used because it affords a simple
  physical picture of turbulence and is therefore readily generalized to
  the inhomogeneous field. Isotropy was assumed for the solar convection
  turbulence field. A convective driving and a diffusion term were worked
  out on this basis and inserted in Heisenberg's field equation. Thus
  it is possible to compute the velocity field in the ionization zone as
  well as the diffusion of this turbulent velocity field up into the solar
  atmosphere. Second, in order to compute the acoustical radiation which
  the velocity field of the ionization zone produces, it was necessary to
  reformulate radiation theory since many misconceptions are associated
  with the conventional viewpoint. An inhomogeneous wave equation was
  obtained giving rigorously the velocities of radiation particles in
  terms of the velocity field producing the turbulence. Because of the
  complexity of the velocity of a turbulent field, the inhomogeneous
  term in the wave equation can be computed only approximately from the
  turbulence field. As a result of the above analysis the turbulence
  velocity field is found to have velocities 0.6 km$sec in agreement
  with observations on the solar granules.' Further, the turbulence
  diffuses only ~oo km into the atmosphere above the convection zone. The
  acoustical radiation for the entire velocity field is found to be
  completely inadequate to heat the corona. The differences between
  this and previous results by Mr. Schwarzschild2 are readil tracked
  down in the theory. Finally, from the reformulation of radiation
  theory it follows that supersonic turbulence in the chromosphere is
  an impossibility unless the entire energy of such a velocity field is
  replenished, say, every 50 seconds, a truly fantastic energy source
  being required. I.R. S. Richardson and M. Schwarzschild, Ap. J. iii,
  351, 1950. 2.Ap. J. 107, 1, 1947. University of Utah, Salt Lake City,
  Utah.

Title: The interstellar dust and gas structures
Authors: Parker, Eugene Newman
Bibcode: 1951PhDT........36P
Altcode:
  An investigation of the statistical properties of the mechanics of the
  dust and gas structures making up the interstellar medium is carried
  out. The aim is to get a comprehensive picture of the general nature
  of the motions and structure of the interstellar material that would
  follow from certain simple assumptions. Comparison with observation
  then shows to what extent the behavior of the interstellar material can
  be accounted for on such a basis and to what extent further factors,
  such as for example magnetic fields, will have to be studied in the
  hope of finding more satisfactory agreement.In I the interstellar gas
  is considered. It is shown that the observed radial motions of the gas
  clouds, if unordered, give too high a kinetic temperature for one to
  account for the observed clumping of the gas into clouds. The stability
  of a clump of gas was investigated using a modification of the ideas
  commonly employed in the virial theorem. It is further shown that given
  discrete gas clouds, the unordered component of their proper motions
  must be even lower to prevent them from collapsing into extremely dense
  structures, possibly clusters of stars, after repeated low velocity
  collisions.In II the observed dust structures are considered and their
  general evolution under the influence of the velocity field of the gas
  and the radiation field is worked out. It is shown that for a continuous
  distribution of dust sizes, certain types of finely striated structures
  cannot be formed.From the inadequacies of this non-magnetic theory,
  one concludes that magnetic fields must play a very significant role in
  the dynamics of the interstellar medium.Finally, in III the collapse
  of a nonturbulent nonrotating dust cloud under its own gravitational
  field is very briefly considered yielding remarkably short collapse
  times of the order of only [...] years.

