Comparison of Global Martian Plasma Models in the Context of MAVEN Observations

Hilary Egan (1) , Yingjuan Ma (2) , Chuanfei Dong (3) , Ronan Modolo (4) , Riku Järvinen (5, 6) , Stephen Bougher (7) , Jasper Halekas (8) , David Brain (9) , James Mcfadden (10) , Jack Connerney (11) , David Mitchell (10) , Bruce Jakosky (9)

1 University of Colorado [Boulder]
2 UCLA - University of California [Los Angeles]
3 Princeton University
4 HELIOS - LATMOS
5 FMI - Finnish Meteorological Institute
6 Department of Electronics and Nanoengineering [Espoo]
7 CLaSP - Department of Climate and Space Sciences and Engineering
8 Department of Physics and Astronomy [Ames, Iowa]
9 LASP - Laboratory for Atmospheric and Space Physics [Boulder]
10 SSL - Space Sciences Laboratory [Berkeley]
11 GSFC - NASA Goddard Space Flight Center

Global models of the interaction of the solar wind with the Martian upper atmosphere have proved to be valuable tools for investigating both the escape to space of the Martian atmosphere and the physical processes controlling this complex interaction. The many models currently in use employ different physical assumptions, but it can be difficult to directly compare the effectiveness of the models since they are rarely run for the same input conditions. Here we present the results of a model comparison activity, where five global models (single‐fluid MHD, multi‐fluid MHD, multi‐fluid electron pressure MHD, and two hybrid models) were run for identical conditions corresponding to a single orbit of observations from the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. We find that low altitude ion densities are very similar across all models, and are comparable to MAVEN ion density measurements from periapsis. Plasma boundaries appear generally symmetric in all models and vary only slightly in extent. Despite these similarities there are clear morphological differences in ion behavior in other regions such as the tail and southern hemisphere. These differences are observable in ion escape loss maps, and are necessary to understand in order to accurately use models in aiding our understanding of the martian plasma environment.

Domaines: Géophysique [physics.geo-ph]; Physique de l'espace [physics.space-ph]

Hilary Egan, Yingjuan Ma, Chuanfei Dong, Ronan Modolo, Riku Järvinen, et al.. Comparison of Global Martian Plasma Models in the Context of MAVEN Observations. Journal of Geophysical Research Space Physics, 2018, 123 (5), pp.3714-3726. ⟨10.1029/2017JA025068⟩. ⟨insu-01779165⟩