Open AccessA method for determining the drift velocity of plasma depletions in the equatorial ionosphere using far‐ultraviolet spacecraft observations
Author(s) -
Park S. H.,
England S. L.,
Immel T. J.,
Frey H. U.,
Mende S. B.
Publication year - 2007
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2007ja012327
Subject(s) - ionosphere , spacecraft , latitude , airglow , earth's magnetic field , geophysics , tracking (education) , plasma , toad , geology , physics , satellite , geodesy , drift velocity , remote sensing , atmospheric sciences , magnetic field , astronomy , biology , psychology , ecology , pedagogy , quantum mechanics
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 automation allows the drift velocities of each bubble to be determined as a function of magnetic latitude, which will give us the capability of retrieving geophysically important parameters such as the electric field, which are believed to vary rapidly with magnetic latitude.