Plasma boundaries at Mars: a 3-D simulation study

Abstract. The interaction of the solar wind with the ionosphere of planet Mars is studied using a three-dimensional hybrid model. Mars has only a weak intrinsic magnetic field, and consequently its ionosphere is directly affected by the solar wind. The gyroradii of the solar wind protons are in the range of several hundred kilometers and therefore comparable with the characteristic scales of the interaction region. Different boundaries emerge from the interaction of the solar wind with the continuously produced ionospheric heavy-ion plasma, which could be identified as a bow shock (BS), ion composition boundary (ICB) and magnetic pile up boundary (MPB), where the latter both turn out to coincide. The simulation results regarding the shape and position of these boundaries are in good agreement with the measurements made by Phobos-2 and MGS spacecraft. It is shown that the positions of these boundaries depend essentially on the ionospheric production rate, the solar wind ram pressure, and the often unconsidered electron temperature of the ionospheric heavy ion plasma. Other consequences are rays of planetary plasma in the tail and heavy ion plasma clouds, which are stripped off from the dayside ICB region by some instability. Key words. Magnetospheric physics (solar wind interactions with unmagnetized bodies) – Space plasma physics (discontinuities; numerical simulation studies)

[1]  H. Rosenbauer,et al.  On the dayside region between the shocked solar wind and the ionosphere of Mars , 1998 .

[2]  M. Acuna,et al.  The magnetic field in the pile‐up region at Mars, and its variation with the solar wind , 2003 .

[3]  R. S. Wolff,et al.  The onset and development of Kelvin-Helmholtz instability at the Venus ionopause , 1980 .

[4]  K. Sauer,et al.  Evidence of an ion composition boundary (protonopause) in bi‐ion fluid simulations of solar wind mass loading , 1994 .

[5]  D. Mitchell,et al.  Oxygen auger electrons observed in Mars' ionosphere , 2000 .

[6]  J. Luhmann,et al.  Venus and Mars: Atmospheres, Ionospheres, and Solar Wind Interactions: Luhmann/Venus and Mars: Atmospheres, Ionospheres, and Solar Wind Interactions , 1992 .

[7]  J. F. Mckenzie,et al.  Critical density layer as obstacle at solar wind ‐ Exospheric ion interaction , 1992 .

[8]  Kenneth G. Powell,et al.  Three-dimensional multispecies MHD studies of the solar wind interaction with Mars in the presence of crustal fields , 2002 .

[9]  C. Russell,et al.  Magnetic field draping enhancement at Venus: Evidence for a magnetic pileup boundary , 2003 .

[10]  H. Rosenbauer,et al.  Study of the solar wind deceleration upstream of the Martian terminator bow shock , 1997 .

[11]  K. Sauer,et al.  Plasma structures at weakly outgassing comets—results from bi-ion fluid analysis , 1996 .

[12]  N. Omidi,et al.  Steepening of kinetic magnetosonic waves into shocklets: Simulations and consequences for planetary shocks and comets , 1990 .

[13]  C. Russell,et al.  Interaction of the solar wind with the planet Mars: Phobos 2 magnetic field observations , 1991 .

[14]  D. Möhlmann,et al.  Plasma boundaries at Mars discovered by the Phobos-2 magnetometers , 1990 .

[15]  Thomas E. Cravens,et al.  The Martian ionosphere in light of the Viking observations , 1978 .

[16]  A. Matthews,et al.  Current Advance Method and Cyclic Leapfrog for 2D Multispecies Hybrid Plasma Simulations , 1994 .

[17]  Rickard N. Lundin,et al.  Aspera/Phobos measurements of the ion outflow from the MARTIAN ionosphere , 1990 .

[18]  Uwe Motschmann,et al.  From a Weak to a Strong Comet — 3D Global Hybrid Simulation Studies , 2002 .

[19]  R. W. Hockney,et al.  Body-fitted electromagnetic PIC software for use on parallel computers , 1995 .

[20]  David L. Mitchell,et al.  The solar wind interaction with Mars: Locations and shapes of the bow shock and the magnetic pile‐up boundary from the observations of the MAG/ER Experiment onboard Mars Global Surveyor , 2000 .

[21]  S. Barabash,et al.  Charge exchange near Mars: The solar wind absorption and energetic neutral atom production , 1997 .

[22]  H. Shimazu Three-dimensional hybrid simulation of solar wind interaction with unmagnetized planets , 2001 .

[23]  V. Riccardo,et al.  Blob Method for Kinetic Plasma Simulation with Variable-Size Particles , 1996 .

[24]  T. Tanaka,et al.  Three-dimensional MHD simulation of the solar wind interaction with the ionosphere of Venus: Results of two-component reacting plasma simulation , 1997 .

[25]  K. Sauer,et al.  Interaction of a magnetized plasma stream with an immobile ion cloud , 1992 .

[26]  S. Barabash,et al.  The solar wind interaction with Mars: Consideration of Phobos 2 mission observations of an ion composition boundary on the dayside , 1991 .

[27]  W. B. Hanson,et al.  Viking electron temperature measurements: Evidence for a magnetic field in the Martian ionosphere , 1988 .

[28]  V. Krasnopolsky Mars' upper atmosphere and ionosphere at low, medium, and high solar activities: Implications for evolution of water , 2002 .

[29]  A. A. Galeev,et al.  Basic plasma physics II , 1983 .

[30]  Janet G. Luhmann,et al.  A post-pioneer Venus reassessment of the Martian dayside ionosphere as observed by radio occultation methods , 1990 .

[31]  L. H. Brace,et al.  Plasma clouds above the ionopause of Venus and their implications , 1982 .

[32]  A. Nagy,et al.  Oxygen ionization rates at Mars and Venus: Relative contributions of impact ionization and charge exchange , 1993 .

[33]  H. Rosenbauer,et al.  Ions of martian origin and plasma sheet in the martian magnetosphere: initial results of the TAUS experiment , 1989, Nature.

[34]  J. F. Mckenzie,et al.  Wave and stability properties of multi-ion plasmas with application to winds and flows , 1993 .

[35]  D. Mitchell,et al.  A proxy for determining solar wind dynamic pressure at Mars using Mars Global Surveyor data , 2003 .

[36]  W. B. Hanson,et al.  The Martian ionosphere as observed by the Viking retarding potential analyzers , 1977 .

[37]  Giovanni Lapenta,et al.  Dynamic and selective control of the number of particles in kinetic plasma simulations , 1994 .

[38]  B. Hultqvist,et al.  First measurements of the ionospheric plasma escape from Mars , 1989, Nature.

[39]  R. Grard,et al.  First measurements of plasma waves near Mars , 1989, Nature.

[40]  K. Powell,et al.  The induced magnetosphere of comet Halley: 4. Comparison of in situ observations and numerical simulations , 1999 .

[41]  H. Rosenbauer,et al.  Large‐scale variations of thermal electron parameters in the solar wind between 0.3 and 1 AU , 1990 .

[42]  J. Kurths,et al.  Magnetic fields near Mars: first results , 1989, Nature.

[43]  K. Szego,et al.  On the interaction between the shocked solar wind and the planetary ions on the dayside of Venus , 1995 .

[44]  K. Powell,et al.  3D Multiscale Mass Loaded MHD Simulations of the Solar Wind Interaction with Mars , 2000 .

[45]  Pekka Janhunen,et al.  Ion escape from Mars in a quasi‐neutral hybrid model , 2002 .

[46]  K. Glassmeier,et al.  Analysis of suprathermal electron properties at the magnetic pile‐up boundary of comet P/Halley , 1989 .

[47]  E. Kallio,et al.  Atmospheric effects of proton precipitation in the Martian atmosphere and its connection to the Mars‐solar wind interaction , 2001 .

[48]  F. S. Johnson,et al.  Viking 1 electron observations at Mars , 1991 .

[49]  H. Lichtenegger,et al.  Model calculations of the planetary ion distribution in the Martian tail , 1998 .

[50]  C. Russell,et al.  Martian bow shock: Phobos observations , 1990 .

[51]  D. Mitchell,et al.  Probing Mars' crustal magnetic field and ionosphere with the MGS Electron Reflectometer , 2001 .

[52]  J. Sauvaud,et al.  Electron plasma environment at comet Grigg‐Skjellerup: General observations and comparison with the environment at comet Halley , 1993 .

[53]  T. Bagdonat,et al.  3D hybrid simulation code using curvilinear coordinates , 2002 .

[54]  S. Brecht Hybrid simulations of the magnetic topology of Mars , 1997 .

[55]  K. Sauer,et al.  The Nature of the Martian `Obstacle Boundary' , 2000 .

[56]  Ness,et al.  Magnetic Field and Plasma Observations at Mars: Initial Results of the Mars Global Surveyor Mission , 1998, Science.

[57]  K. Powell,et al.  THE SOLAR WIND INTERACTION WITH MARS: RESULTS OF THREE-DIMENSIONAL MHD STUDIES , 2001 .

[58]  K. Powell,et al.  The solar wind interaction with Mars: results of three-dimensional three-species MHD studies , 2001 .