Local electrodynamics of a solar eclipse at the magnetic equator in the early afternoon hours

Abstract

The path of maximum obscuration for the annular solar eclipse of January 15, 2010, crossed the magnetic equator at Trivandrum, India, in the early afternoon hours. A strong counter-electrojet was observed shortly after maximum obscuration. Moreover, as the eclipse passed overhead, the F region density peak underwent a large amplitude vertical oscillation. At the same moment, there was an oscillation in the zonal electric field inferred from the magnetometer data. The electric field turned westward after the time of maximum obscurity, reaching its largest westward value one hour before the end of the local eclipse. We show that these data are consistent with a fast eastward moving local neutral wind dynamo generated by a low pressure system postulated to have been triggered by the cold temperatures in the region of maximum obscuration.