CaltechAUTHORS
Published December 28, 2023 | Version Published
Journal Article Open

Discrete Aurora at Mars: Insights Into the Role of Magnetic Reconnection

Creators

  • 1. ROR icon Laboratory for Atmospheric and Space Physics
  • 2. ROR icon California Institute of Technology
  • 3. ROR icon University of Michigan–Ann Arbor
  • 4. ROR icon Dublin Institute For Advanced Studies
  • 5. ROR icon Goddard Space Flight Center
  • 6. ROR icon University of Liège
  • 7. ROR icon University of Iowa
  • 8. ROR icon University of California, Berkeley

Abstract

Discrete aurora are sporadic emissions of light originating in Mars upper atmosphere. We report nadir imaging observations from MAVEN's Imaging UltraViolet Spectrograph which identify the conditions which trigger electron precipitation causing these events. Prior studies have shown that discrete aurora events in the strong crustal magnetic field region in the southern hemisphere are the brightest and most repeatable compared to events occurring outside the region. Our new data set offers a more complete and accurate characterization of aurora in this area. The region of strongest crustal fields is composed of two distinct magnetic regions, with magnetic fields in opposite directions; discrete aurora events trigger in one region after dusk and in the other before dawn. Magnetic reconnection in these two adjacent regions with the draped interplanetary field may open the crustal fields in these regions during opposing local times. Particle precipitation can then cause discrete aurora at the observed times and locations.

Copyright and License

© 2023. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivsL icense, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Acknowledgement

The MAVEN mission is supported by NASA in association with the University of Colorado and NASA's Goddard Space Flight Center. JCG and LS acknowledge support from the Belgian Federal Science Policy Office, with financial and contractual coordination by the ESA PRODEX Office (PEA Grant 4000140863).

Data Availability

In accordance with the AGU data policy, the data used in this study may be obtained from the Planetary Atmospheres Node of the Planetary Data System at https://atmos.nmsu.edu/PDS/data/PDS4/MAVEN/ using the filenames containing the keyword “apoapse” and version “v13.” Special data products produced for this work are available at the CU Scholar repository (Jain & Schneider, 2023).

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Geophysical Research Letters - 2023 - Johnston - Discrete Aurora at Mars Insights Into the Role of Magnetic Reconnection.pdf

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Additional details

Identifiers

ISSN
1944-8007

Funding

National Aeronautics and Space Administration
Belgian Federal Science Policy Office
4000140863
European Space Agency