Properties of Electron Distributions in the Martian Space Environment

G. Andreone; J. S. Halekas; D. L. Mitchell; C. Mazelle; J. Gruesbeck

doi:10.1029/2021JA029404

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Properties of Electron Distributions in the Martian Space Environment

Journal article

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Peer reviewed

Properties of Electron Distributions in the Martian Space Environment

G. Andreone, J. S. Halekas, D. L. Mitchell, C. Mazelle and J. Gruesbeck

Journal of geophysical research. Space physics, Vol.127(1), e2021JA029404

01/01/2022

DOI: 10.1029/2021JA029404

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Abstract

Electron and magnetic field measurements from the Mars atmosphere and volatile environment (MAVEN) mission are utilized to study the interaction between Mars and the solar wind. Instruments like the solar wind electron analyzer (SWEA) aboard MAVEN measure properties of the electron environment over a broad range of electron energies. Measurements at low electron energies include contributions from spacecraft photoelectrons and secondary electrons that must be accounted for to accurately characterize the environment. We developed an algorithm to identify and remove secondary electron contamination to improve estimates of electron densities and temperature. We then compiled global maps of average electron density, temperature, and temperature anisotropy under different conditions, considering quasi-parallel and quasi-perpendicular bow shocks and upstream solar wind Alfven Mach number. Higher temperature anisotropy is observed for quasi-perpendicular shock crossings, as expected. We find significant electron temperature anisotropy upstream of the bow shock for quasi-perpendicular shock crossings, suggesting a heating mechanism, such as that provided by electromagnetic waves. We analyzed the influence of hi and low Alfven Mach number conditions and found the electron plasma beta to be the only electron property significantly affected. We studied the relationship between the electron distribution function and the generation of instabilities and conclude that the upstream Alfven Mach number influences the stability of electron distributions in the Martian environment.

Physical Sciences

Astronomy & Astrophysics

Science & Technology

Details

Title: Subtitle: Properties of Electron Distributions in the Martian Space Environment
Creators: G. Andreone - University of Iowa
J. S. Halekas - University of Iowa
D. L. Mitchell - Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA
C. Mazelle - Université Fédérale de Toulouse Midi-Pyrénées
J. Gruesbeck - Goddard Space Flight Center
Resource Type: Journal article
Publication Details: Journal of geophysical research. Space physics, Vol.127(1), e2021JA029404
DOI: 10.1029/2021JA029404
ISSN: 2169-9380
eISSN: 2169-9402
Publisher: Amer Geophysical Union
Number of pages: 15
Grant note: 80NSSC20K0571 / Solar System Workings program MAVEN contract French space agency CNES; Centre National D'etudes Spatiales
Language: English
Date published: 01/01/2022
Academic Unit: Physics and Astronomy
Record Identifier: 9984428671102771

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