MAVEN Observations of Ionospheric Irregularities at Mars

C. M. Fowler , L. Andersson , S. R. Shaver , J. P. Thayer , J. D. Huba , R. Lillis , M. E. Usanova , J. Espley , R. E. Ergun , J. Mcfadden , P. R. Mahaffy , J. E. P. Connerney , M. Benna , M. Elrod , D. L. Mitchell , C. Mazelle (1) , B. M. Jakosky

1 IRAP - Institut de recherche en astrophysique et planétologie

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.

Keywords: ionosphere; instability; Mars; irregularity; MAVEN

Domains: Sciences of the Universe [physics]

C. M. Fowler, L. Andersson, S. R. Shaver, J. P. Thayer, J. D. Huba, et al.. MAVEN Observations of Ionospheric Irregularities at Mars. Geophysical Research Letters, 2017, 44, pp.10,845-10,854. ⟨10.1002/2017GL075189⟩. ⟨insu-03676934⟩