Thermospheric Wind Changes During and After the March 17, 2013 Geomagnetic Storm

Abstract:

The thermospheric wind response to a major geomagnetic storm event on March 17, 2013 has been studied using the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM). The model results have also been compared with neutral wind measurements to investigate dynamic changes of winds during the storm and their recover after the storm. The model shows that the storm-time winds are greatly enhanced and become mostly westward at middle and low latitudes. There is a significant UT dependence and north-south asymmetry in the wind response to the storm although the storm occurred near March equinox. The TIEGCM also shows that the recover of neutral winds after the storm depends on local time and location. Daytime winds at middle and low latitudes recover faster than at other times and locations. The recover of winds takes about 12-18 hours, which is relatively faster than the recover of thermospheric temperature and composition and ionospheric electron densities that lasts for more than a day. The physical processes that drive the storm-time changes in winds and determine the recover have also been studied.