MAVEN Observations of Ionospheric Irregularities at Mars. Issue 21 (4th November 2017)

• Record Type: Journal Article
• Authors: Fowler, C. M.; Andersson, L.; Shaver, S. R.; Thayer, J. P.; Huba, J. D.; Lillis, R.; Usanova, M. E.; Espley, J.; Ergun, R. E.; Mcfadden, J.; Mahaffy, P. R.; Connerney, J. E. P.; Benna, M.; Elrod, M.; Mitchell, D. L.; Mazelle, C.; Jakosky, B. M.
• Is Part Of: Geophysical research letters. Volume 44:Issue 21(2017)
• Page Start: 10, 845
• Page End: 10, 854
• Publication Date: 2017-11-04
• Subjects: ionosphere -- instability -- Mars -- irregularity -- MAVEN; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL075189
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Ionospheric irregularities associated with horizontal magnetic fields below 200 km altitude are observed at Mars. Plasma density modulations of up to 200% are observed during such events and appear correlated with fluctuations in the magnetic field. The observed fluctuations are likely Doppler shifted and represent spatial structures at length scales of 15–20 km or less. Conditions in the Martian ionosphere below 200 km are synonymous with the terrestrial E region, where ionospheric irregularities have been extensively studied. Interestingly, the irregularities at Mars appear to be electromagnetic in nature, in contrast to the electrostatic nature of irregularities at Earth. It is currently unclear what the primary drivers of these irregularities at Mars are, and further study is needed to explain these important phenomenon within the Martian ionosphere. Key Points: Example of ionospheric irregularities in the Martian ionosphere below 200 km altitude is presented Statistical analysis of similar events shows peak occurrences at dawn and dusk Cause of irregularities is unclear, particularly as irregularities appear to be electromagnetic in nature