Neutral winds in the high latitude winter F‐region: Coordinated observations from ground and space

Abstract

Coordinated measurements of the F‐Region neutral wind field in the northern (winter) polar cap are reported using instrumentation on board the Dynamics Explorer (DE‐2) satellite and the Ulster College ground‐based Fabry‐Perot interferometer sited at Svalbard (UFPI). The satellite observations provide the full neutral wind vector along the track of the polar orbiting spacecraft with the meridional component measured by the Fabry‐Perot Interferometer (FPI) and the zonal component measured by the Wind and Temperature Spectrometer (WATS). The UFPI observations provide a set of four horizontal wind components in the cardinal directions which may be merged to give two individual neutral wind vectors for each measurement cycle (duration ∼30 minutes). A comparison of data from the ground and spaceborne sensors for simultaneous, near common‐volume observations indicates good agreement between the observational techniques. Simultaneous observations made when the Svalbard observatory and DE‐2 were in different local time sectors of the northern polar cap provide a more detailed “snap‐shot” of the neutral circulation pattern than possible using either technique alone. The measurements show the presence of a large‐scale, anti‐cyclonic vortex system on the evening and day‐side sectors of the winter polar cap.