First Detection of Kilometer‐Scale Density Irregularities in the Martian Ionosphere
C. M. Fowler, J. W. Bonnell, Shaosui Xu, M. Benna, M. K. Elrod, J. McFadden, D. L. Mitchell, J. R. Espley, L. Andersson, R. E. Ergun, R. J. Lillis, B. M. Jakosky
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.