Concerning the origin of signatures in dayside equatorial ground magnetograms
- Applied Physics Laboratory, Johns Hopkins University, Laurel, Maryland (United States)
- Solar Terrestrial Environment Laboratory, Toyokawa (Japan)
- Department of Earth and Planetary Sciences, Kyushu University, Fukuoka (Japan)
- Los Alamos National Laboratory, Los Alamos, New Mexico (United States)
Previous reports suggest that north/south interplanetary magnetic field (IMF) turnings are the predominant cause of north/south fluctuations in dayside equatorial ground magnetograms. We compare 210{degree} Magnetic Meridian (MM) ground magnetograms with simultaneous IMP 8 solar wind and LANL geosynchronous energetic electron observations during 1993 and 1994 to search for this effect. About one third of the northward equatorial magnetic field enhancements can be associated with increases in the solar wind dynamic pressure, a second third with substorm onset as measured by energetic electron injections, and the final third with southward IMF turnings. An alternative explanation can be found for most enhancements associated with north/south IMF variations but not for enhancements associated with solar wind dynamic pressure variations or substorm onsets. Our results suggest that dayside equatorial ground magnetograms may be used to monitor both solar wind dynamic pressure variations and nightside substorm onsets. {copyright} 1998 American Geophysical Union
- OSTI ID:
- 643256
- Journal Information:
- Journal of Geophysical Research, Vol. 103, Issue A4; Other Information: PBD: Apr 1998
- Country of Publication:
- United States
- Language:
- English
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