Modeling negative ionospheric storm effects caused by thermospheric disturbances observed in satellite UV images

Abstract

The ionospheric behavior over Podkamennaya, Russia, during the geomagnetic storm of October 14, 1981, is modeled subject to the constraints provided by foF2 measurements and by the thermospheric O/N2 ratio deduced from a DE 1 FUV image taken at 0540 UT. The (nonunique) diurnal variation of O/N2 deduced from the model is consistent with the thermospheric composition disturbance zone observed in the DE 1 image having moved over Podkamennaya during the early morning hours, producing a reduction of O/N2 (referred to a column density of N2 of 1017 cm-2) to a value of less than 0.2 before recovering to a value of 0.6 during the afternoon hours. Although the data are insufficient to provide a unique solution, the results demonstrate the utility of satellite-based FUV images in the study of thermospheric and ionospheric disturbances produced by geomagnetic storms. Copyright 2001 by the American Geophysical Union.