Magnetic Impulse Event: A Detailed Case Study of Extended Ground and Space Observations

We present a detailed discussion of an extensive set of ground and spacecraft data that are used to elucidate the initiation, evolution, and termination of a magnetic impulse event (MIE) on June 6, 1997. Beginning at approximately 1600 UT, nearly twenty ground magnetometers in the northern and the southern hemispheres measured the MIE. The MIE was accompanied by a traveling convection vortex (TCV) in both hemispheres. The event originated in the pre-noon magnetosphere (~ 10 MLT) and traveled sunward (eastward) at 1-3 km/sec (at the Earth's surface) across magnetic local noon. Particle data from the DMSP spacecraft indicate that the TCV originated in the magnetosphere low latitude boundary layer (LLBL).