HR: 0800h
AN: SM21A-0300    [Abstracts]
TI: On-Line Explorer-45 Plasmapause-Crossing Database and Related Ionospheric Satellite Measurements
AU: Grebowsky, J M
EM: joeseph.m.grebowsky@nasa.gov
AF: NASA/Goddard Space Flight Center, Planetary Magnetospheres Laboratory, Code 695, Solar Systems Exploration Division, Greenbelt, MD 20771, United States
AU: * Bilitza, D
EM: bilitza@mail630.gsfc.nasa.gov
AF: GMU/Goddard Space Flight Center, Heliospheric Physics Laboratory, Code 672, Heliophysics Science Division, Greenbelt, MD 20771, United States
AU: Benson, R F
EM: robert.f.benson@nasa.gov
AF: NASA/Goddard Space Flight Center, Geospace Physics Laboratory, Code 673, Heliophysics Science Division, Greenbelt, MD 20771, United States
AU: Webb, P A
EM: pwebb@pop600.gsfc.nasa.gov
AF: GEST/UMBC/Goddard Space Flight Center, Space Weather Laboratory, Code 674, Heliophysics Science Division, Greenbelt, MD 20771, United States
AU: Shah, S S
EM: jewels18080@yahoo.com
AF: National Space Club Scholars Program/Goddard Space Flight Center, Heliospheric Physics Laboratory, Code 672, Heliophysics Science Division, Greenbelt, MD 20771, United States
AB: Near equatorial-plane plasmapause crossings (below 5.2 RE) were determined from Explorer-45 electric-field measurements [Maynard and Cauffman, JGR, 78, 4745, 1973]. The crossings were determined when the electric field detector went out of saturation outbound or into saturation inbound. A hard copy listing of these crossings was compiled by N. Maynard and was available to us. This information has now been converted to digital form and is available on-line from the National Space Science Data Center. We plan to use these data, in conjunction with ISIS-2 ion mass spectrometer and ISIS-1 and -2 topside-sounder measurements, to infer H+ dominance through the low-latitude trough boundaries in order to address the ambiguity in the literature as to the relationship between midlatitude trough structures and the plasmapause. Some studies have shown a close relationship between the electron-density trough and the plasmapause, e.g., the comparison of ionospheric tomographic imaging and EUV/IMAGE plasmapause determinations by Yizengaw and Moldwin [GRL, 32, L09105, 2005], while others show only a rough correlation, e.g., the comparison of Explorer-45 plasmapause crossings and Ariel-4 and ISIS-2 ionospheric data by Grebowsky et al. [Planet. Space Sci., 24, 1177, 1976]. The magnetic-field models in these databases were very simple, however, and didn't account for inflation of the equatorial fields. Explorer-45, ISIS-1 and ISIS-2 orbit data have been added to the GSFC Space Physics Data Facility SSCWeb orbits/conjunctions system so that we are now able to search for magnetic conjunction between these satellites, using up-to-date magnetic-field models, and then select cases where a plasmapause crossing is accompanied by ion density measurements and/or electron-density profiles on the same field line in the ionosphere.
DE: 2483 Wave/particle interactions (7867)
DE: 2716 Energetic particles: precipitating
DE: 2730 Magnetosphere: inner
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2768 Plasmasphere
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting