HR: 17:00h
AN: SM14A-04    [Abstracts]
TI: A Potential Physical Process for Substorm Expansion Onset
AU: * Lui, A T
EM: Tony.Lui@jhuapl.edu
AF: Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723 United States
AB: The fact that there are two existing paradigms for substorm expansion onset is the fundamental justification for NASA's MIDEX mission THEMIS. The five satellites measuring plasma environment in the magnetotail combined with extensive coverage of aurora from ground stations are posed to distinguish these two paradigms. In this presentation, a combination of plasma instabilities that can lead to current disruption in the magnetotail is proposed as a potential physical process for substorm expansion onset in the near-Earth region. Observational evidence in agreement with this idea as well as theory and simulation developed for it are briefly reviewed. Observations from THEMIS that can falsify or bolster this idea will also be discussed.
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 2744 Magnetotail
DE: 2753 Numerical modeling
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005