HR: 0830h
AN: SM51C-0533    [PDF]
TI: Pulsed Electric Fields at the Nightside Plasmapause
AU: * Kim, K
EM: khan@khu.ac.kr
AF: Kyung Hee University, Department of Astronomy and Space Science,, Yongin, 449-701 Korea, Republic of
AU: Lee, D
EM: dhlee@khu.ac.kr
AF: Kyung Hee University, Department of Astronomy and Space Science,, Yongin, 449-701 Korea, Republic of
AU: Cattell, C
EM: cattell@belka.space.umn.edu
AF: University of Minnesota, School of Physics and Astronomy, 116 Church Street S.E., Minneapolis, MN 55455 United States
AU: Wygant, J
EM: wygant@ham.space.umn.edu
AF: University of Minnesota, School of Physics and Astronomy, 116 Church Street S.E., Minneapolis, MN 55455 United States
AU: Mozer, F
EM: fmozer@sunspot.ssl.berkeley.edu
AF: University of California, Space Science Laboratory, Berkeley, CA 94720 United States
AB: It has been suggested that the magnetospheric energy is strongly absorbed near the boundary region between hot and cold plasmas and/or near the steep density gradient region. The plasmapause is considered as such a region. Motivated by this suggestion, we surveyed the electric field data from the Polar satellite for March-May 1997. During these periods, the Polar orbits at geocentric distances of 3-7 Re were inbound passes from the northern tail lobe to the plasmasphere in the 2100-0300 magnetic local time (MLT) sector. We found 15 transient electric field enhancements in the form of pulsed signature at/near the plasmapause. Some of the pulsed electric field (PEF) events were accompanied by the magnetic field perturbations. The electric fields of the pulsed structure were roughly polarized in the direction perpendicular to the ambient magnetic field. The PEF events are distributed in the 2100-0300 MLT and from $\sim$5.6\deg\ to $\sim$27.6\deg\ in magnetic latitude. The peak amplitudes of the PEF events are $\sim$2-14 mV/m larger than the averaged electric field value in the plasma sheet. The 10 (3) PEF events were observed while the AL index was gradually increasing (decreasing). The remaining 2 events occurred during the interval of suddenly decreasing AL. We suggest that the PEF events are a manifestation of the energy absorption at/near the plasmapause and discuss whether their source is associated with magnetospheric substorm because their occurrence was on the nightside.
DE: 2712 Electric fields (2411)
DE: 2740 Magnetospheric configuration and dynamics
DE: 2764 Plasma sheet
DE: 2768 Plasmasphere
DE: 2788 Storms and substorms
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting