Zonal wind velocity profiles in the equatorial electrojet derived from phase velocities of type II radar echoes

Abstract

Zonal wind profiles in the daytime equatorial electrojet are inferred from the Doppler shifts of type II radar echoes observed at the Jicamarca Radio Observatory (JRO) in Perú. The inference is based on a three-dimensional electrostatic potential model. The model includes anomalous effects and is constrained by radar and magnetometer data. The amplitude and phase of the calculated zonal wind profiles are in general agreement with representative wind profiles measured by the WINDII instrument on board the Upper Atmosphere Research Satellite (UARS). The calculated winds also have the same general characteristics as zonal wind profiles measured by rocket-borne chemical release experiments. However, the magnitude of the latter are larger than the former. The temporal behavior of the calculated zonal winds suggests a downward phase progression with a roughly semidiurnal period.