HR: 1340h
AN: SA13A-1082    [Abstracts]
TI: A method for determining the drift velocity of plasma depletions in the equatorial ionosphere using far-ultraviolet spacecraft observations: initial results
AU: * England, S L
EM: england@ssl.berkeley.edu
AF: University of California, Berkeley Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Immel, T J
EM: immel@ssl.berkeley.edu
AF: University of California, Berkeley Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Park, S H
EM: sunghongpark@ssl.berkeley.edu
AF: University of California, Berkeley Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Frey, H U
EM: hfrey@ssl.berkeley.edu
AF: University of California, Berkeley Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Mende, S B
EM: mende@ssl.berkeley.edu
AF: University of California, Berkeley Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720, United States
AB: The Far-Ultraviolet Imager (IMAGE-FUV) on-board the NASA IMAGE satellite has been used to observe plasma depletions in the nightside equatorial ionosphere. Observations from periods around spacecraft apogee, during which equatorial regions are visible for several hours, have allowed the velocity of these plasma depletions to be determined. A new method for determining the velocity of these depletions using an image analysis technique, Tracking Of Airglow Depletions (TOAD), has been developed. TOAD allows the objective identification and tracking of depletions. The automation of this process has also allowed for the tracking of a greater number of depletions than previously achieved without requiring any human input, which shows that TOAD is suitable for use with large data sets and for future routine monitoring of the ionosphere from space. Furthermore, this allows the drift velocities of each depletion to be determined as a function of magnetic latitude as well as local time. Previous ground-based airglow observations from a small number of locations have indicated that the drift velocities of depletions may vary rapidly with magnetic latitude. Here we shall present the first results from TOAD of this shear in drift velocities from our global sample of depletion drift velocities.
DE: 0310 Airglow and aurora
DE: 2415 Equatorial ionosphere
DE: 2439 Ionospheric irregularities
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting