HR: 13:55h
AN: SM42D-02    [PDF]
TI: Plasmaspheric Dynamics: Solar-Wind/IMF and Sub-Auroral Coupling
AU: * Goldstein, J
EM: jerru@alum.dartmouth.org
AF: Southwest Research Institute, Space Science (Div 15), SwRI 6220 Culebra Road, San Antonio, TX 78238 United States
AU: Sandel, B
EM: sandel@arizona.edu
AF: University of Arizona, Lunar and Planetary Lab, University of Arizona, Tucson, AZ 85721 United States
AU: Kozyra, J
EM: jukozyra@umich.edu
AF: University of Michigan, Space Physics Research Lab University of Michigan, Ann Arbor, MI 48109 United States
AU: Mannucci, A
EM: Tony.Mannucci@jpl.nasa.gov
AF: Jet Propulsion Laboratory, Jet Propulsion Lab California Institute of Technology, Pasadena, CA 91109 United States
AB: The images produced by the IMAGE extreme ultraviolet (EUV) imager have provided the first global view of plasmaspheric dynamics, including the process of erosion and the formation and evolution of drainage plumes. The traditional picture holds that the zero-order behavior of the plasmasphere is described by superposition of corotation and solar-wind-driven sunward convection. We test this long-standing hypothesis by comparing EUV images and the output of a plasmapause evolution model driven by a time-varying Volland-Stern electric potential field. Volland-Stern simulations of two June 2001 erosion events reproduce the EUV plasmapause position on the dawnside, but place it too far from Earth near dusk, implying strong duskside flows not in the model. Low-altitude DMSP data show that duskside flows are often enhanced by the sub-auroral polarization stream (SAPS) phenomenon which couples the ring current, ionosphere and plasmasphere together. Our simple ad-hoc SAPS model corrects the duskside plasmapause position in the model. Thus, both convection and SAPS play a significant role in the global dynamics of the plasmasphere during geomagnetic disturbances. Analysis of DMSP data and model results indicate that SAPS flows may be responsible for a duskside "undulation" of the plasmapause observed on 17 April 2002. There is also evidence that SAPS plays a significant role in the creation of "tongue"-like regions of enhanced ionospheric/plasmaspheric total electron content (TEC) observed by the GPS network to extend poleward from low latitudes.
DE: 2712 Electric fields (2411)
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2760 Plasma convection
DE: 2768 Plasmasphere
DE: 2778 Ring current
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting