HR: 16:50h
AN: SM24A-03 INVITED     [Abstracts]
TI: The role of the plasmasphere in the dynamics of ionospheric density structures
AU: * Yizengaw, E
EM: ekassie@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, UCLA, P.O. Box 951567 3845 Slichter Hall, Los Angeles, CA 90095, United States
AU: Moldwin, M B
EM: mmoldwin@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, UCLA, P.O. Box 951567 3845 Slichter Hall, Los Angeles, CA 90095, United States
AB: Coordinated ground-based and satellite observations are of great importance for understanding the electrodynamics of inner-magnetospheric density structures. Examples of these structures are storm enhanced density (SED) and plasmasphere drainage plumes resulting from the erosion of the plasmasphere boundary layer by sub-auroral disturbance electric fields. SED or localized enhancement of TEC results from a poleward redistribution of dusk-sector plasma from the low-latitude region during the early stage of a strong geomagnetic disturbance. While ground-based observations with GPS TEC and ISR combined with low-altitude satellite observations such as DMSP, TOPEX, and JASON see enhanced density structure, IMAGE EUV magnetospheric imagery from space detect this enhanced density as a pronounced bright region in the inner plasmapshere. In this paper, we present coordinated ground-based and satellite observations results showing the role of the plasmasphere and plasmapause in the dynamics of ionospheric density structures. This includes the simultaneous global observations of ground-based GPS TEC and ionospheric TEC observed by the JASON and TOPEX satellites to experimentally determine the percentage contribution of the plasmapshere to the ground- based GPS TEC and thus to the degradation of navigation and communication systems. We find the plasmasphere can contribute significantly to round-based GPS TEC.
DE: 2730 Magnetosphere: inner
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2768 Plasmasphere
DE: 2774 Radiation belts
DE: 2778 Ring current
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly