The Impact of Crustal Magnetic Fields on the Thermal Structure of the Martian Upper Atmosphere
Yelle, R. V.
Koskinen, T. T.
AffiliationUniv Arizona, Lunar & Planetary Lab
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationThe Impact of Crustal Magnetic Fields on the Thermal Structure of the Martian Upper Atmosphere 2018, 853 (2):L33 The Astrophysical Journal
Rights© 2018. The American Astronomical Society. All rights reserved.
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AbstractUsing the Mars Atmosphere and Volatile Evolution Neutral Gas and Ion Mass Spectrometer data, we investigate the possible impact of crustal magnetic fields on the thermal structure of the Martian upper atmosphere. Our analysis reveals a clear enhancement in temperature over regions with strong crustal magnetic fields during two deep dip campaigns covering the periods of April 17-22 and September 2-8, both in 2015. Several controlling factors, such as solar EUV irradiance, relative atomic O abundance, and non-migrating tides, do not help to explain the observed temperature enhancement, and a magnetically driven scenario is favored. We evaluate the roles of several heating mechanisms that are likely modulated by the presence of crustal magnetic fields, including Joule heating, ion chemical heating, as well as electron impact heating via either precipitating solar wind electrons or locally produced photoelectrons. The respective heating rates of these mechanisms are substantially lower than the solar EUV heating rate, implying that none of them is able to interpret the observations.
VersionFinal published version
SponsorsNational Science Foundation of China (NSFC) [41525015, 41774186, 41504133]; Science and Technology Development Fund of Macau SAR (FDCT) [039/2013/A2, 082/2015/A3]