Statistical models of perpendicular Ion currents and pressure in the Inner magnetosphere: SCATHA, CRRES and Polar data

The pressure of the plasma in inner magnetosphere is directly related to the variation of the ring current as represented by the Dst geomagnetic index. The local ion pressure is well measured by ion flux measurements and the currents are functions of the spatial gradients in that pressure. We use data from ion instruments on several satellites to build a statistical model of the pressure and currents of the major ion species. This study includes six years of data from the CEPPAD IPS and the CAMMICE MICS sensors on the ISTP Polar satellite and 1.5 years of data from a similar MICS sensor on the CRRES spacecraft. We supplement the Polar data with total ion fluxes observed by the SCATHA satellite for L~5-8. The data from the Polar and CRRES satellites provide detailed information on the pressure and current contributions during geomagnetic storms for the four different ion species: H+, He+, He++, and O+. We compare the results of this statistical model with previous empirical models and the radial profiles during specific geomagnetic storms. This information is then complemented with the ten years of SCATHA observations to provide insights into the solar cycle variation of the ion pressure distribution.