HR: 0800h
AN: SA51B-0523    [Abstracts]
TI: Residence time of flux tubes in the auroral oval
AU: * Burns, A G
EM: aburns@ucar.edu
AF: HAO/NCAR, NCAR/HAO P.O. Box 3000, Boulder, CO 80309-3000, United States
AU: Lotko, W
EM: William.Lotko@dartmouth.edu
AF: Dartmouth College, Dartmouth College, Thayer School of Engineering, Hanover, NH 03755, United States
AU: Wang, W
EM: wbwang@ucar.edu
AF: HAO/NCAR, NCAR/HAO P.O. Box 3000, Boulder, CO 80309-3000, United States
AU: Wiltberger, M
EM: wiltbemj@ucar.edu
AF: HAO/NCAR, NCAR/HAO P.O. Box 3000, Boulder, CO 80309-3000, United States
AU: Solomon, S C
EM: stans@ucar.edu
AF: HAO/NCAR, NCAR/HAO P.O. Box 3000, Boulder, CO 80309-3000, United States
AU: Killeen, T L
EM: killeen@ucar.edu
AF: HAO/NCAR, NCAR/HAO P.O. Box 3000, Boulder, CO 80309-3000, United States
AB: Ion outflow helps to maintain the density of the magnetosphere by moving ions up from the ionosphere. There are two sets of mechanisms involved in producing the outflow that has been observed by satellites such as FAST. The first involves moving ions up into the energization region and the second involves the energization processes themselves. These processes, and particularly the former ones, take time to act on the flux tube to allow outflow to occur. Such a time delay raises the question: do flux tubes remain in the auroral oval long enough for these energization processes to occur? In this presentation we address this issue by presenting auroral residence times calculated by a simple flux tube trajectory model. This model uses known ion drifts (in this case from the LFM model) and a known auroral oval (in this presentation it is calculated from electron densities at the z=-2.5 pressure surface of TING) to determine how long flux tubes have been in the auroral oval. The results are presented as a contour map of residence times that can later be compared with ion outflow simulations to see if the flux tubes spend enough time in the auroral oval to produce the required ion outflows.
DE: 2400 IONOSPHERE (6929)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2437 Ionospheric dynamics
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting