HR: 0800h
AN: SM11A-0326    [Abstracts]
TI: The Auroral Acceleration Region: FAST Observations in the THEMIS Era
AU: * Strangeway, R J
EM: strange@igpp.ucla.edu
AF: IGPP/UCLA, 405 Hilgard Ave., Los Angeles, CA 90095, United States
AU: Angelopoulos, V
EM: vassilis@ucla.edu
AF: IGPP/UCLA, 405 Hilgard Ave., Los Angeles, CA 90095, United States
AU: Carlson, C W
EM: cwc@ssl.berkeley.edu
AF: SSL/UCB, 7 Gauss Way, Berkeley, CA 94720, United States
AU: McFadden, J P
EM: mcfadden@ssl.berkeley.edu
AF: SSL/UCB, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Ergun, R E
EM: ergun@lasp.colorado.edu
AF: LASP, Univ. of Colorado, Boulder, CO 80303, United States
AU: Mende, S B
EM: mende@ssl.berkeley.edu
AF: SSL/UCB, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Frey, H U
EM: hfrey@ssl.berkeley.edu
AF: SSL/UCB, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Donovan, E
EM: edonovan@ucalgary.ca
AF: Univ. of Calgary, Dept. of Physics and Astronomy, SB636, Calgary, AB T2N 1N4, Canada
AU: Russell, C T
EM: ctrussel@igpp.ucla.edu
AF: IGPP/UCLA, 405 Hilgard Ave., Los Angeles, CA 90095, United States
AU: Glassmeier, K
EM: k-h.glassmeier@tu-bs.de
AF: TU Braunschweig, Pockelsstr. 14, Braunschweig, D-38106, Germany
AU: Auster, H
EM: uli.auster@tu-bs.de
AF: TU Braunschweig, Pockelsstr. 14, Braunschweig, D-38106, Germany
AB: More than 11 years after being launched in August 1996, the FAST spacecraft continues to acquire data within the auroral acceleration region (AAR). With the launch of the THEMIS spacecraft and the building of the associated ground-station network, these observations take on added significance. In particular the THEMIS spacecraft provide observations of the "drivers" of the field-aligned currents, Alfvén waves, and plasma populations that ultimately result in the emissions and magnetic field perturbations observed by the THEMIS ground-stations, but only after the particles and fields have been processed through the AAR. FAST is ideally suited to provide the observations of the AAR, where the electromagnetic energy flux associated with large-scale field-aligned currents and Alfvén waves is partially converted to particle energy flux (e.g., inverted-V and wave-accelerated electrons). FAST also observes the consequences of these energy fluxes as ionospheric plasma outflows. As part of the instrument commissioning phase the THEMIS spacecraft were fortunate to observe a substorm on March 23, 2007. Shortly after the substorm onset FAST flew through the AAR. FAST observed a strong westward flow channel, together with typical signatures of the AAR. The flow channel was bounded by a pair of field-aligned currents. A similar signature was observed at THEMIS altitudes, but this appeared to be associated with the passage over the THEMIS spacecraft of the western most edge of the substorm current-wedge system. In this presentation we explore how field-aligned currents and related particle signatures as observed at FAST are related to magnetospheric dynamics as observed by the THEMIS spacecraft and ground-stations.
DE: 2721 Field-aligned currents and current systems (2409)
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2740 Magnetospheric configuration and dynamics
DE: 2790 Substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting