Heating of the low-latitude upper atmosphere caused by the decaying magnetic storm ring current

Abstract

This study investigates the charge-exchange mechanism by which part of the energy contained in the magnetic storm ring current is injected into the low-latitude upper atmosphere and contributes to the energy balance in this region. The resulting temperature perturbation is estimated for a specific magnetic storm event and compared with that deduced from satellite drag data. It is found that the charge-exchange mechanism gives the correct temporal behavior of the magnetic storm associated changes in the upper-atmospheric temperature but cannot account for the magnitude of the observed temperature perturbation. An upper bound to the contribution of this mechanism to the low-latitude geomagnetic activity effect is estimated to be 30 per cent during a large magnetic storm.