Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020
Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020
EPSC Abstracts
Vol. 14, EPSC2020-408, 2020
https://doi.org/10.5194/epsc2020-408
Europlanet Science Congress 2020
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Superthermal electron deposition on the Mars nightside during ICMEs

Shaosui Xu1, Shannon Curry1, David Mitchell1, Janet Luhmann1, Robert Lillis1, and Chuanfei Dong2
Shaosui Xu et al.
  • 1University of California, Berkeley, Space Sciences Laboratory, Berkeley, California, United States of America (shaosui.xu@ssl.berkeley.edu)
  • 2Department of Astrophysical Sciences and Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ, United States of America

Superthermal electron precipitation is one of the main sources supporting the Mars nightside ionosphere. It is expected that solar wind electron fluxes are to increase significantly during interplanetary coronal mass ejections (ICME) and therefore an enhanced nightside ionospheric density. This study is to quantify the variation of the precipitating and deposited electron fluxes during five of the most extreme ICMEs encountered by Mars Global Surveyor (MGS). We find energy fluxes correlate better with the upstream dynamic pressure proxy than number fluxes and electron fluxes increase more at high energies, which means electrons tend to have a lower peak production altitude during storm times. The precipitating and net/deposited fluxes are increased up to an order of magnitude from low to high dynamic pressures. The estimated total electron content (TEC) is a few times of 1014 m-2 for quiet times and on the order of 1015 m-2 for storm times, with an enhancement up to an order of magnitude locally near strong crustal fields. Crustal magnetic fields have an effect on the deposited fluxes with more prominent magnetic reflection over strong magnetic fields during quiet periods, which is significantly reduced during storm times. Lastly, we estimate a global energy input from downward fluxes of 1.3×108 W and 5.5×108 W and the globally deposited energy from net fluxes of 2.3×107 W and 1.6×108 W for quiet and storm time periods, a factor of 4 and 7 enhancement globally, respectively, but up to an order of magnitude locally near strong crustal fields.

How to cite: Xu, S., Curry, S., Mitchell, D., Luhmann, J., Lillis, R., and Dong, C.: Superthermal electron deposition on the Mars nightside during ICMEs, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-408, https://doi.org/10.5194/epsc2020-408, 2020.