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Electron Energetics in the Martian Dayside Ionosphere: Model Comparisons with MAVEN DataThis paper presents a study of the energetics of the dayside ionosphere of Mars using models and data from several instruments on board the Mars Atmosphere and Volatile EvolutioN spacecraft. In particular, calculated photoelectron fluxes are compared with suprathermal electron fluxes measured by the Solar Wind Electron Analyzer, and calculated electron temperatures are compared with temperatures measured by the Langmuir Probe and Waves experiment. The major heat source for the thermal electrons is Coulomb heating from the suprathermal electron population, and cooling due to collisional rotational and vibrational CO2 dominates the energy loss. The models used in this study were largely able to reproduce the observed high topside ionosphere electron temperatures (e.g., 3000 K at 300 km altitude) without using a topside heat flux when magnetic field topologies consistent with the measured magnetic field were adopted. Magnetic topology affects both suprathermal electron transport and thermal electron heat conduction. The effects of using two different solar irradiance models were also investigated. In particular, photoelectron fluxes and electron temperatures found using the Heliospheric Environment Solar Spectrum Radiation irradiance were higher than those with the Flare Irradiance Spectrum Model-Mars. The electron temperature is shown to affect the O2(+) dissociative recombination rate coefficient, which in turn affects photochemical escape of oxygen from Mars.
Document ID
20170003172
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Sakai, Shotaro (Kansas Univ. Kansas City, KS, United States)
Andersson, Laila (Colorado Univ. Boulder, CO, United States)
Cravens, Thomas E. (Kansas Univ. Kansas City, KS, United States)
Mitchell, David L. (California Univ. Berkeley, CA, United States)
Mazelle, Christian (Toulouse Univ. France)
Rahmati, Ali (Kansas Univ. Kansas City, KS, United States)
Fowler, Christopher M. (Colorado Univ. Boulder, CO, United States)
Bougher, Stephen W. (Michigan Univ. Ann Arbor, MI, United States)
Thiemann, Edward M. B. (Colorado Univ. Boulder, CO, United States)
Epavier, Francis G. (Colorado Univ. Boulder, CO, United States)
Fontenla, Juan M. (Northwest Research Associates, Inc. Boulder, CO, United States)
Mahaffy, Paul R. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Connerney, John E. P. (Adnet Systems, Inc. Greenbelt, MD, United States)
Jakosky, Bruce M. (Colorado Univ. Boulder, CO, United States)
Date Acquired
April 7, 2017
Publication Date
July 23, 2016
Publication Information
Publication: Journal of Geophysical Research: Space Physics
Volume: 121
Issue: 7
ISSN: 2169-9380
Subject Category
Lunar and Planetary Science and Exploration
Report/Patent Number
GSFC-E-DAA-TN40365
Funding Number(s)
CONTRACT_GRANT: NNH10CC04C
CONTRACT_GRANT: NNG12PL17C
Distribution Limits
Public
Copyright
Other
Keywords
magnetic topology
dayside ionosphere
Electron