Abstract 9619733 Lyons This project will make use of data from several spacecraft, ground-based optical sensors and ionospheric radars to study the dynamic response of the Earth's magnetosphere to variations in the solar wind. In particular the CANOPUS chain of meridian scanning photometers, the SuperDARN (Dual Auroral Radar Network) and the Sonde Stromfjord ionospheric radar will all be used to monitor the precipitation of particles from the inner edge of the magnetospheric plasma sheet, thereby determining its ionospheric footprint as a function of time. The position of the plasma sheet further from Earth will simultaneously be monitored by the ISTP/POLAR and HEO spacecraft. The dynamical behavior of the plasma sheet will then be correlated with the solar wind magnetic field and plasma parameters as measured by the ISTP/WIND, ISTP/GEOTAIL and IMP-8 spacecraft. This project contributes to the National Space Weather Program. ***