EGUsphere

Copernicus Publications

Göttingen, Germany

10.5194/egusphere-2023-1799

Ionospheric density depletions around crustal fields at Mars and their connection to ion frictional heating

Madanian

Hadi

https://orcid.org/0000-0002-2234-5312

¹ Hesse

Troy

¹ Duru

Firdevs

² Pilinski

Marcin

https://orcid.org/0000-0002-1509-3268

¹ Frahm

Rudy

Laboratory for Atmospheric and Space physics, University of Colorado Boulder, Boulder, CO 80303, USA

Coe College, Cedar Rapids, IA 52402, USA

Space Physics and Engineering Division, Southwest Research Institute, San Antonio, TX 78238, USA

National Aeronautics and Space Administration

n/a

17 08 2023

2023 1 19

2023

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/

This article is available from https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1799/

The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1799/egusphere-2023-1799.pdf

Mars’ ionosphere is formed through ionization of the neutral atmosphere by solar irradiance, charge exchange, and electron impact. Observations by Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft have shown a highly dynamic ionospheric layer at Mars impacted by loss processes including ion escape, transport, and electron recombination. The crustal fields at Mars can also significantly modulate the ionosphere. We use MAVEN data to perform a statistical analysis of ionospheric density depletions around crustal fields. Events mostly occur when the crustal magnetic field are radial, outward, and with a mild preference towards east in the planetocentric coordinates. We show that events near crustal fields are typically accompanied by an increase in suprathermal electrons within the depletion, either throughout the event or as a short-lived electron beam. However, no correlation between the changes in the bulk electron densities and suprathermal electron density variations is observed. Our analysis indicates that the temperature of the major ionospheric species, O2+, increases during most of the density depletion events, which could indicate that some ionospheric density depletions around crustal fields are a result of ion frictional heating.