First Detection of Kilometer‐Scale Density Irregularities in the Martian Ionosphere. Issue 22 (18th November 2020)

• Record Type: Journal Article
• Authors: Fowler, C. M.; Bonnell, J. W.; Xu, S.; Benna, M.; Elrod, M.; McFadden, J.; Mitchell, D. L.; Espley, J.; Andersson, L.; Ergun, R. E.; Lillis, R.; Jakosky, B.
• Is Part Of: Geophysical research letters. Volume 47:Issue 22(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-11-18
• Subjects: Ionospheric irregularities -- Ionospheric instability -- Mars -- Ionosphere; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2020GL090906
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Plasma instabilities have been studied for many decades in the terrestrial ionosphere via remote and in‐situ measurement techniques. The study of these kilometer‐scale instabilities has provided crucial insight into coupling between the neutral atmosphere and ionosphere. A special high‐time cadence observation mode developed for the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission has demonstrated for the first time that kilometer‐scale density fluctuations exist at Mars. Density and associated magnetic fluctuations are observed to occur both in and out of phase with each other, suggesting that multiple instability mechanisms are active, similar to Earth. The unique solar wind interaction with Mars and its localized crustal magnetic fields appears to play an important role in the formation of these irregularity events, which form preferentially during meridionally pointing magnetic field within the ionosphere. This is in contrast to Earth where the strong dipole magnetic field dominates in the terrestrial ionosphere. Key Points: Kilometer‐scale ionospheric density irregularities are fully resolved for the first time at Mars A range of irregularity characteristics suggests that multiple formation mechanisms are active at Mars, as at Earth The unique interaction between Mars and the solar wind appears to play an important role in irregularity formation