Spatially Small Scale Ionospheric Currents at Mars.
Thursday, 26 May 2016: 5:00 PM
Laila Andersson1, Mehdi Benna2, Gina A DiBraccio2, John E P Connerney2, Christopher M Fowler3, Adam K Woodson3, Tristan David Weber4, Robert Ergun5 and Paul R Mahaffy2, (1)University of Colorado at Boulder, Boulder, CO, United States, (2)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (3)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (4)University of Michigan, Ann Arbor, MI, United States, (5)Univ Colorado, Boulder, CO, United States
Abstract:
In the lower Martian ionosphere the neutral density increases with decreasing altitude. Ions, and then electrons, decouple from the magnetic field, allowing for the closure of field aligned currents. Observations at the terminator by the MAVEN mission show that the ionosphere is filamented with narrow currents that have spatial scales of the order of the ion gyro radius. Using case studies, this work shows at which altitude the ions decouple from the magnetic field and start to move with the neutrals. The observed file aligned currents change the conductivity as through impact ionization but cross-terminator transport also can change the conductivity. With the MAVEN mission the highly variable ionosphere at Mars can be studied.
