Modeling the Solar Wind Plasma Interaction with Gerasimovich Magnetic Anomaly on the Moon

Friday, 19 December 2014
Shahab Fatemi, Charles Lue, Mats Holmstrom, Martin Wieser and Stas Barabash, IRF Swedish Institute of Space Physics Kiruna, Kiruna, Sweden
We study the solar wind plasma interaction with Gerasimovich magnetic anomaly on the Moon. We use a three-dimensional hybrid model of plasma and an empirical model of magnetic anomalies. We examine the effects of low and high dynamic pressures on this interaction while the Gerasimovich magnetic anomaly is located at nearly 30o and 60o solar zenith angles. We find that for the low dynamic pressure the crustal fields deflect the solar wind plasma around and form a plasma void at very close distances to the Moon (below 20 km above the surface). This is while during the high dynamic pressure the plasma void disappears and the solar wind plasma is less deflected. The deflection is associated with an electrostatic potential difference of nearly 250 and 150 V on the lunar surface during the low and high dynamic pressures, respectively, which are consistent with the observations.