HR: 11:20h
AN: SA22A-05    [Abstracts]
TI: Electric fields and zonal winds in the equatorial ionosphere inferred from 30,000 individual CHAMP orbits
AU: * Alken, P
EM: alken@colorado.edu
AF: National Geophysical Data Center, E/GC 325 Broadway, Boulder, CO 80305, United States
AU: * Alken, P
EM: alken@colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences, 216 UCB, Boulder, CO 80309, United States
AU: Maus, S
EM: stefan.maus@noaa.gov
AF: National Geophysical Data Center, E/GC 325 Broadway, Boulder, CO 80305, United States
AU: Maus, S
EM: stefan.maus@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, 216 UCB, Boulder, CO 80309, United States
AB: The Equatorial Electrojet (EEJ) is an eastward current in the ionospheric E-region, flowing along the dip equator on the day-side. This current system produces a strong signal in the magnetic measurements of the CHAMP satellite. The resulting latitudinal current profiles can be used to place constraints on the electric fields and zonal winds in the equatorial ionosphere. More than six years of CHAMP observations are now available, comprising more than 30,000 equator crossings. In an earlier study we had shown that the eastward current density at the magnetic equator is a good proxy for the electric field. To further improve the method, we now use the MSIS and IRI models to compute the conductivity in a meridional cross-section of the ionosphere and solve the governing differential equation directly for the eastward electric field and zonal wind. This leads to more accurate electric field estimates and places useful constraints on the ambient zonal wind.
DE: 1541 Satellite magnetics: main field, crustal field, external field
DE: 2409 Current systems (2721)
DE: 2411 Electric fields (2712)
DE: 2415 Equatorial ionosphere
DE: 2437 Ionospheric dynamics
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting