HR: 14:55h
AN: SA22B-06    [PDF]
TI: Observing the Storm Time Ring Current from Low Earth Orbit
AU: * Rich, F J
EM: frederick.rich@hanscom.af.mil
AF: Air Force Research Lab (VSBXP), 29 Randolph Road, Hanscom AFB, MA 01731 United States
AU: Sexton, E
EM: ethan.sexton@hanscom.af.mil
AF: Radex, Inc., 3 Preston Place, Bedford, MA 01731 United States
AB: Recent spacecraft of the Defense Meteorological Satellite Program (DMSP) have carried vector magnetometers. We have developed a technique for analyzing magnetic field data obtained at 840 km altitude to determine the disturbance magnetic fields due to the ring current. This disturbance field signature is similar to the DST index. We show the technique for the computation and the results of the computations for a few recent storm periods. Typically, in the early hours of a storm, the disturbance field stronger on the evening side than on the morning side, and it becomes equally strong on the morning and evening sides late in the storm. This behavior has been reported from ground-based magnetometers and is consistent with the ring current development observed from the Image spacecraft. We demonstrate that the space-based magnetometer is a useful supplement to the ground-based sensors in studying the progress of a geomagnetic storm. It is free of signatures due to ionospheric and ground currents and can provide data over areas of the world with few ground-based observatories.
DE: 2409 Current systems (2708)
DE: 2415 Equatorial ionosphere
DE: 2494 Instruments and techniques
DE: 2778 Ring current
SC: SPA - Aeronomy [SA]
MN: 2003 Fall Meeting