THE RESPONSE OF THE MAGNETOSPHERE TO AN INTERPLANETARY SHOCK: GROUNDBASED OBSERVATIONS OF THE SUDDEN IMPULSE ON SEPTEMBER 24, 1998

P. Chi1, Guan Le1, J. Raeder1, C. T. Russell1, E. Zesta1, K. Yumoto2,
  H. Kawano2, K. Kitamura2, V. Angelopoulos3 and M. Moldwin4

1University of California, Los Angeles, CA,  USA
2Kyushu University, Fukuoka, Japan
3University of California, Berkeley, CA,  USA
4Florida Institute of Technology, Florida, USA
 
 The strong interplanetary shock wave that intersected the front of the
magnetosphere at about 2344 UT on Sept. 24, 1998, launched a compression of
the magnetosphere that was followed around the globe by a new generation of
magnetometers with rapid sampling and precise GPS-synchronized timing.
Magnetometers of these chains included those in the Circum Pan Pacific
Magnetometer Network, those in the IGPP/LANL array, those in the MEASURE
array and those in the MACCS array.  The event exhibited all the classical
signatures of an SI including the preliminary decrease before the main
increase in the H-component.  The ability to model this event and its
induced ionospheric currents using an MHD code allows us to compare the
compression as it is seen in the magnetosphere with the response of the
ionospheric currents.
 
1. GA 3.08
2. Magnetotail Dynamics