HR: 14:40h
AN: SM13E-05    [Abstracts]
TI: Activity Dependent O+ Transport Paths From the Ionosphere to the Ring Current
AU: * Peterson, W
EM: Bill.Peterson@lasp.colorado.edu
AF: LASP, University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Andersson, L
EM: laila.andersson@lasp.colorado.edu
AF: LASP, University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Callahan, B
EM: Bryan.Callahan@lasp.colorado.edu
AF: LASP, University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Elkington, S
EM: Scot.Elkington@lasp.colorado.edu
AF: LASP, University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Winglee, R
EM: winglee@ess.washington.edu
AF: University of Washington, Dept Earth and Space Sciences, Seattle, WA 98195-1310, United States
AU: Scudder, J
EM: jack-scudder@uiowa.edu
AF: University of Iowa, Dept Physics and Astronomy, Iowa City, IA 52240-0000, United States
AU: Collin, H
EM: fortimas@znet.com
AF: Lockheed Martin, ADCS B255, 3251 Hanover St, Palo Alto, CA 94304-1191, United States
AB: Energetic O+ has important dynamic effects on the ring current. Insights into the effects of O+ on ring current dynamics have come primarily from models, not observations. Here we report observations made on the Polar spacecraft by the Toroidal Imaging Mass-Angle Spectrograph (TIMAS) which has measured the flux and energy distribution of escaping O+, cast in auroral boundary coordinates. Comparison with ISEE -1 observations of O+ in the plasma sheet, other recent observations, and multi-fluid simulations of the magnetosphere suggest that there are two distinct pathways for the energization and transport of O+ from the dayside ionosphere to the plasma sheet: 1) Energization and transport over the polar cap into the central plasma sheet which our analysis suggests is significant only during geomagnetically active times; and 2) Energization and transport in three dimensional magnetospheric fields during geomagnetically quiet times that leads to a significant O+ population on the plasma sheet flanks. The consequences of the suggested activity-dependant O+ transport path and transport of O+ in boundary related coordinates have not been previously explored.
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2447 Modeling and forecasting
DE: 2730 Magnetosphere: inner
DE: 2764 Plasma sheet
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting