Equatorial ionosphere-thermosphere system during geomagnetic storms

This paper presents the recent progress in understanding the behavior of the structure and dynamics of the equatorial ionosphere-thermosphere system (EITS) under disturbed geomagnetic conditions. The storm-time modifications in the key parameters and major phenomena of the ionized and neutral domains of the system, which prevail with distinctive time delays with reference to the onset of enhanced geomagnetic activity and excess energy deposition at high latitudes, are traced broadly to fluid dynamical and electrodynamical couplings of the high latitude-low latitude upper atmospheres. Some of the major unsettled issues concerning the storm-time EITS that merit continued and concerted investigations for a comprehensive and quantitative empirical and theoretical understanding are highlighted