The Influence of the Martian Bow Shock on Heavy Planetary Ions

Friday, 19 December 2014
Blake Christian Johnson1, Michael Warren Liemohn1, Gabriella Stenberg2, Hans Nilsson2, Robin Ramstad2 and Markus Fraenz3, (1)University of Michigan, Ann Arbor, MI, United States, (2)IRF Swedish Institute of Space Physics Kiruna, Kiruna, Sweden, (3)Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany
Due to the extent of Mars’ exosphere and the large gyroradii of some heavy planetary ions, it is expected that some atmospheric ions will encounter the bow shock. However, the effect that the bow shock has on these heavy ions is relatively unstudied. Mars Express (MEX) ion data is examined to determine whether significant differences exist in the velocity space distributions of energetic planetary ions inside and outside of the shock. To allow for determination of the solar wind motional electric field (Esw) using Mars Global Surveyor (MGS) magnetometer data, the study is focused on the time interval from early 2004 to late 2006 when MEX and MGS overlapped. For each 192 second measurement, an average velocity is assigned to heavy ions at high energies (> 2 keV). The possibility that there is turbulence in the magnetosheath altering the paths of heavy pickup ions will be tested by comparing flight directions relative to the direction of Esw in the magnetosheath to flight directions relative to the Esw direction upstream of the bow shock.