HR: 1400h
AN: SM23C-02    [Abstracts]
TI: Do Global Auroral Images and Simultaneous Magnetospheric Observations Support the NENL Model of Substorm Onset?
AU: * Fillingim, M O
EM: matt@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AU: Parks, G K
AF: Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AU: Lee, E
AF: Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AU: Mende, S B
AF: Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720-7450, United States
AB: Correlations between global auroral images and in-situ measurements in the plasma sheet and magnetotail have led to many new insights into how the magnetosphere and ionospheric auroral region are coupled. Several studies have shown that intense auroral emission in the ionosphere is well correlated with plasma sheet disturbances characterized by one or more of the following: large ion velocity moments, enhancements in the energetic ion and electron fluxes, increases in plasma temperature, and high frequency fluctuations in the magnetic field. In addition global images provide unambiguous timing of auroral brightenings and direction and speed of propagation of auroral forms. The timing and propagation determined from images, in turn, can be used to put the plasma sheet observations in context. We show several examples of auroral substorms and other auroral activity observed by global auroral imagers and simultaneous, in-situ near-Earth plasma sheet plasma and magnetic field observations. We conclude that when a spacecraft in the near-Earth plasma sheet (X < 20 RE) detects plasma sheet activity, it is in a region magnetically connected to intense auroral emission in the ionosphere. This implies a near Earth source (near 10 RE) and that plasma sheet disturbances propagate tailward as regions of intense auroral emission migrate poleward. This result is mostly inconsistent with the NENL model of substorm onset. Several case studies which were originally interpreted to support the NENL model are re-interpreted to be inconsistent with this model. Future refinements to the NENL model must address these inconsistencies.
UR: http:sprg.ssl.berkeley.edu/matt/AGUS2007/NENL/
DE: 2704 Auroral phenomena (2407)
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2740 Magnetospheric configuration and dynamics
DE: 2764 Plasma sheet
DE: 2790 Substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly