HR: 12:05h
AN: SM42A-08    [Abstracts]
TI: The Connection Between Transpolar Arcs and the Recovery Phase of Substorms
AU: * Bryant, C R
EM: bryant@phys.ucalgary.ca
AF: Institute for Space Research, Dept. of Physics and Astronomy University of Calgary 2500 University Dr. NW, Calgary, AB T2N 1N4 Canada
AU: Murphree, J S
EM: murphree@phys.ucalgary.ca
AF: Institute for Space Research, Dept. of Physics and Astronomy University of Calgary 2500 University Dr. NW, Calgary, AB T2N 1N4 Canada
AU: Mende, S B
EM: mende@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California Berkeley, California 94720, Berkeley, CA 94720 United States
AB: Contrasting the well observed and much discussed growth and expansion phases, the recovery phase has received much less attention and little is known about it. Conventional wisdom says that the recovery phase is the relaxation of the magnetosphere back to a quiet auroral configuration. Optically, the recovery phase appears to start when the auroral bulge stops moving poleward but observations indicate that the recovery phase has considerable activity. Measurements have established the basic relationships between auroral recovery phase features and magnetotail regimes such as the double oval phenomenon. Observations obtained using the FUV instruments on the IMAGE satellite show that transpolar arcs (TPA's) are often associated with the recovery phase of substorms. These TPA's are controlled by the interplanetary magnetic field (IMF), in particular the By component. Examples of recovery phases emphasizing the timing of the TPA's compared to onset and the TPA's relationship to the IMF will be the focus of this presentation.
DE: 2704 Auroral phenomena (2407)
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting