Equatorial Electric Fields Derived from Swarm Magnetometer Data

Abstract:

The Swarm Level-2 operational equatorial electric field (EEF) product
is producing estimates of the EEF for each dayside orbit of all three
satellites. The EEF plays a crucial role in E and F region daytime
equatorial ionospheric dynamics. It is responsible for driving the
equatorial electrojet (EEJ) current system, equatorial vertical ion drifts,
and the equatorial ionization anomaly (EIA). The EEF is recovered by
analyzing the EEJ signature seen in the Swarm absolute scalar magnetometer
(ASM) data. We will present first results of Swarm-derived EEJ currents
and their corresponding EEF estimates, compare the results between
satellites, and finally validate them against independent ground
measurements. We will further compare the magnetometer-derived EEF in
the E-region with measurements from the Electric Field Instrument (EFI) to
explore vertical gradients in the equatorial electric field.