Characterizing Mars's Magnetotail Topology With Respect to the Upstream Interplanetary Magnetic Fields

Shaosui Xu , David L. Mitchell , Tristan Weber , David A. Brain , Janet G. Luhmann , Chuanfei Dong , Shannon M. Curry , Yingjuan Ma , Gina A. Dibraccio , Jasper Halekas , Yaxue Dong , Christian Mazelle (1)

1 IRAP - Institut de recherche en astrophysique et planétologie

The canonical picture of the magnetotail of unmagnetized planets consists of draped interplanetary magnetic fields (IMFs) forming opposite-directed lobes, separated by the current sheet. DiBraccio et al. (2018, https://doi.org/10.1029/2018GL077251) showed that Mars's magnetotail has a twist departing from this picture. Magnetohydrodynamic (MHD) results suggest that the asymmetry in how open field lines connected to the planet populate the tail causes the apparent twist. To validate this interpretation, we compare the tail topology determined from MHD simulations to that inferred from data collected by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, in particular, how each topology responds to the upstream IMF orientation. The occurrence rates for open topology from both data and MHD vary with IMF polarities in a similar fashion as the tail twisting. This suggests that Mars's crustal fields have a global effect on the magnetosphere configuration, supporting the picture of a "hybrid" magnetotail that is partly induced/draped and partly intrinsic/planetary in origin.

Mots clés: Sun-Mars interaction; tail topology; MAVEN; magnetosphere; magnetic reconnection

Domaines: Planète et Univers [physics]

Shaosui Xu, David L. Mitchell, Tristan Weber, David A. Brain, Janet G. Luhmann, et al.. Characterizing Mars's Magnetotail Topology With Respect to the Upstream Interplanetary Magnetic Fields. Journal of Geophysical Research Space Physics, 2020, 125, ⟨10.1029/2019JA027755⟩. ⟨insu-03673163⟩