CONTROL ID: 1487415
TITLE: Modeling of Mars' ionospheric electrodynamics under various local magnetic field topologies
ABSTRACT BODY: The interactions between Mars' unique crustal magnetic fields and upper atmospheric electrons, ions and neutrals lead to the formation of currents in the ionospheric dynamo region. These interactions involve elastic and inelastic collisions between ions, electrons and neutrals in the presence of varying pressures, temperatures and densities. The current remanent fields embedded in the crust provide Mars with a very rich magnetic topology with significant variations in term of geometry and magnitude on the order of a few tens to hundreds of kilometers spatially and several order of magnitude in amplitude. Here we present mesoscale, three-dimensional, multi-fluid, self-consistent simulations of Mars' ionospheric electrodynamics in the dynamo region ($\sim$100--400~km altitude), where differential motion of ions and electrons occurs. Our investigations focus on the influence of the magnetic field strength and geometry, and neutral wind speeds, on the dynamo current. We look in particular at the influence of the magnetic field magnitude through simpler, uniform geometries. In addition, our model is able to simulate highly non-uniform magnetic fields involving cusps and loops. To achieve these geometries, we position a small magnetic dipole in the crust and are able to produce representative field configurations. The work presented here investigates the effects of thermospheric neutral winds, magnetic topologies, and variations in dayside and nightside on the formation and evolution of ionospheric currents on Mars. These simulation predictions will be compared to the data from Mars Atmospheric and Volatile EvolutioN (MAVEN) mission starting in early 2015. They will ultimately help to assess the ionospheric effects on future missions to the Red Planet.

CURRENT SECTION/FOCUS GROUP: Planetary Sciences
CURRENT SESSION: P004. Atmosphere of Mars: New Findings from Modeling and Observations
INDEX TERMS: [0343] ATMOSPHERIC COMPOSITION AND STRUCTURE / Planetary atmospheres, [2437] IONOSPHERE / Ionospheric dynamics, [6225] PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS / Mars, [5440] PLANETARY SCIENCES: SOLID SURFACE PLANETS / Magnetic fields and magnetism.
AUTHORS/INSTITUTIONS: J.A. Riousset, C.S. Paty, J.M. Hale, Department of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA;
R.J. Lillis, M.O. Fillingim, S. England, Space Sciences Laboratory, University of California Berkeley, Berkeley, CA;
P. Withers, Astronomy Department, Boston University, Boston, MA;
SPONSOR NAME: Jeremy Riousset
CONTACT (E-MAIL ONLY): riousset@gatech.edu
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