Storm-time plasma signatures observed by IMAGE/MENA and comparison with a global physics-based model

Abstract

We present energetic neutral atom (ENA) fluxes measured by the medium energy neutral atom (MENA) imager onboard the IMAGE satellite for the geomagnetic storm of 21 October 2001 at energies of 6 and 12 keV. The fluxes indicate strong low altitude emissions close to the Earth and a nightside peak close to local midnight. The fluxes are compared with theoretical ENA fluxes calculated using the ring current-atmosphere interaction model (RAM). We find good quantitative agreement between MENA data and RAM results, both of which indicate a peak in ENA emissions on the nightside, close to local midnight which varies in radial location between ∼2 and ∼5 Re during the period of study. We demonstrate the validity of comparing RAM results with MENA data and pave the way for further study of plasma sheet entry to the inner magnetosphere during storm-times. Copyright 2005 by the American Geophysical Union.