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MPIS_PROJECTS:
Mars Express: ASPERA-3
Abstract:
A detailed model‐model comparison between the results provided by a multispecies and a multifluid magnetohydrodynamic (MHD) code for the escape of heavy ions in the Martian‐induced magnetosphere is presented. The results from the simulations are analyzed and compared against a statistical analysis of the outflow of heavy ions obtained by the Mars Atmosphere and Volatile EvolutioN/Suprathermal and Thermal Ion Composition instrument over an extended period of time in order to estimate the influence of magnetic forces in the ion escape. Both MHD models are run with the same chemical reactions and ion species in a steady state mode under idealized solar conditions. Apart from being able to reproduce the asymmetries observed in the ion escape, it is found that the multifluid approach provides results that are closer to those inferred from the ion data. It is also found that the j × B force term is less effective in accelerating the ions in the models when compared with the Mars Atmosphere and Volatile EvolutioN results. Finally, by looking at the contribution of the plume and the ion escape rates at different distances along the tail with the multifluid model, it is also found that the escape of heavy ions has important variabilities along the tail, meaning that the apoapsis of a spacecraft studying atmospheric escape can affect the estimates obtained.
