Plasmaspheric depletion, refilling, and plasmapause dynamics: A coordinated ground-based and IMAGE satellite study

Abstract

This paper presents a coordinated ground-based magnetometer and IMAGE satellite study of plasma mass density and plasmapause location on L shells between 2.39 and 6.54 throughout an extended interval of moderate geomagnetic activity from 5 to 17 May 2001. Storm-time plasmaspheric depletion is monitored using three different data sets, and our results show the importance of local time history effects on plasma depletion, including determining that shorter intervals of enhanced convection do not necessarily cause all meridian sectors to be depleted. Analysis of ground-based magnetometer derived mass density implies that poststorm refilling is not a steady process through the dayside sector. Our results also suggest that refilling may be a two-stage process, operating with a much increased rate on the third day of clear refilling. Comparisons between time-dependent ground-based magnetometer cross-phase and IMAGE RPI determined plasma mass density profile evolution imply the presence of an enhanced heavy ion population in the inner plasmatrough during an active refilling interval. These results further demonstrate the potential of using ground-based magnetometer data to study cold plasma dynamics. Copyright 2006 by the American Geophysical Union.