Global Ambipolar Potentials and Electric Fields at Mars Inferred From MAVEN Observations - Archive ouverte HAL Access content directly
Journal Articles Journal of Geophysical Research: Space Physics Year : 2021

Global Ambipolar Potentials and Electric Fields at Mars Inferred From MAVEN Observations

, , , , , , , , (1)
1
Shaosui Xu
  • Function : Author
David L. Mitchell
  • Function : Author
Yingjuan Ma
  • Function : Author
Tristan Weber
  • Function : Author
David A. Brain
  • Function : Author
Jasper Halekas
Suranga Ruhunusiri
  • Function : Author
Gina Dibraccio
  • Function : Author

Abstract

The motion of charged particles is governed by electromagnetic forces at high altitudes at Mars and thus the characterization of electrostatic potential and electric fields is important for understanding ion escape at Mars. In this study, we utilize measurements from the Mars Atmosphere and Volatile EvolutioN mission to derive electrostatic potentials above the collisional atmosphere at Mars. We find averaged potentials to be up to ∼100 V in the magnetosheath and down to ∼-70 V in the tail, with respect to the upstream. We then derive electric fields based on averaged potential maps, ranging ∼0.01-0.1 V/km. These data-derived electric fields are in good agreement with ambipolar electric fields from a multi-fluid magnetohydrodynamic (MHD) model. MHD results also reveal that these large electric fields mainly originate from the electron pressure gradient in the magnetosheath and in the transition region from the hot solar wind flow to the cold ionospheric flow. This work provides the first data-based characterization of global ambipolar electric fields at Mars (outside of the main ionosphere).
Not file

Dates and versions

insu-03672337 , version 1 (19-05-2022)

Identifiers

Cite

Shaosui Xu, David L. Mitchell, Yingjuan Ma, Tristan Weber, David A. Brain, et al.. Global Ambipolar Potentials and Electric Fields at Mars Inferred From MAVEN Observations. Journal of Geophysical Research: Space Physics, 2021, 126, ⟨10.1029/2021JA029764⟩. ⟨insu-03672337⟩
2 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More