THE RESPONSE OF THE MAGNETOSPHERE TO AN INTERPLANETARY SHOCK:
GLOBAL SIMULATIONS OF THE SEPTEMBER 24,1998 SUDDEN IMPULSE EVENT

J RAEDER, C T Russell (both at the Institute of Geophysics and Planetary Physics. University of California, 405 Hilgard Ave, Los Angeles, CA 90095, USA, email: jraeder@igpp.ucla.edu)

 

A very strong interplanetary shock was observed by the Wind spacecraft on September 24, 1998, 2221 UT. The resulting sudden impulse (SI) was observed by several magnetospheric spacecraft, as well as by ground magnetometers. This event gives us a unique opportunity to study the response of the magnetosphere using our global magnetosphere - ionosphere model, and to compare our results in detail with the observations Besides providing an assessment of the accuracy and robustness of our model for such an event. We will also present a more complete picture of the magnetospheric response as the observations alone could provide. In particular, we will discuss the propagation of the SI initiated waves through the magnetosphere, SI modifications to the current systems, and the causes of the ground magnetic perturbations.