Fennell, J. F.,
Co-Authors: J. L. Roeder, J. B. Blake, R. H. W. Friedel, G. D. Reeves, M. Henderson, M. Grande, T. A. Fritz, and S. Livi,
Title: Multiple Satellite Study of the May 1998 Magnetic Storm Event: Ring Current Response,
Reference: AGU Fall Meeting, San Francisco, CA, 6-10 December, 1998.
Reference Type: Contributed Talk
CEPPAD: true
CAMMICE: true
RAPID: false
Abstract:
One of the problems of performing ring current studies with in-situ data has been the poor spatial/temporal sampling of the inner magnetosphere that has been provided by single satellite studies. Generally, the recent (since 1984) studies of the ring current have relied on single satellites in geotransfer or higher apogee orbits with periods of 12 hours or more. The recent observations taken by the Polar satellite in an 18 hour orbit are representative of this problem. For this study we combine the detailed composition observations from Polar CAMMICE experiment with HEO (94-026, 95-034, and 97-068) satellite observations taken in ~12 hour orbits at different local times. The HEO instruments provide only proton observations and their coverage occurs roughly in the pre-noon/pre-midnight, post-noon/post-midnight and dawn/ dusk regions of the inner magnetosphere. Polar covers the pre-noon/pre-midnight region. The minimum Dst for the event occurred on May 4, 1998 near 0700 UT. Polar was outbound through the near noon ring current region from ~0400 UT until it exited the plasma sheet and entered the magnetosheath (during the shock) near 0615 and again near 0645 UT. It did not resample the ring current until after 1920 UT on May 4. Adding the HEO data provides ring current traversals near 0000, 0500, 0600, 0800, 0830,1100, and 1400 UT on May 4 during the $D_{ST}$ minimum and early storm recovery. These combined observations will be presented and discussed in terms of the development of the storm main phase and its initial recovery.
