HR: 11:15h
AN: SM12B-04    [Abstracts]
TI: Electrodynamics of M-I Coupling during the Main Phase of Superstorms
AU: * Huang, C Y
EM: cheryl.huang@hanscom.af.mil
AF: Air Force Research Laboratory, 29 Randolph Road, Hanscom AFB, MA 01731 United States
AU: Burke, W J
EM: william.burke2@hanscom.af.mil
AF: Air Force Research Laboratory, 29 Randolph Road, Hanscom AFB, MA 01731 United States
AU: Lin, C S
EM: chin.lin@hanscom.af.mil
AF: Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 01467 United States
AB: During the main phase of superstorms (Dst less than -200 nT) the mapping of magnetic field lines from the ionosphere to the magnetosphere is strongly and asymmetrically distorted by ring-current penetration close to Earth (Tsyganenko et al., 2003). Consequences of this distortion appear in plasma, particle and field measurements by DMSP satellites in low-Earth orbit and the CRRES satellite in the inner magnetosphere. They are manifest through the generation of low-energy ion populations and field-aligned currents with intensities above 1 A/m. The low energy ions are observed in both the ionosphere and magnetosphere near the dawn meridian below L = 2, well earthward/equatorward of the plasma sheet/auroral electron boundaries. DMSP satellites observe the intense paired sheets of field-aligned current in both the evening and dawn local time sectors. In some instances, precipitating electrons with energies well below 1 keV carry the upward current. Stopping at altitudes > 150 km, they support several tens of mhos of Pedersen but negligible Hall conductance. In such cases ground magnetometers measurements provide scant evidence that several terajoules of electromagnetic energy was deposited in the mid-latitude ionosphere. We provide examples of these main-phase phenomena observed during the superstorms of March 1991, April 2000 and October 2003 and discuss some implications for the equations of state used to describe the transport of ring-current plasma.
DE: 2712 Electric fields (2411)
DE: 2730 Magnetosphere--inner
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2760 Plasma convection
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting