SuperDARN, WINDII and WACCM-X neutral and ion winds observed at high latitudes during geomagnetic disturbances

In 2018 a band of strong westward zonal wind (400–600 m s−1) was found in both daytime polar thermospheres, at 65° – 70° geographic latitude. It was imbedded in the eastward zonal wind background and because of its narrow longitudinal structure was called a “wind wall”. The observations were made with the Wind Imaging Interferometer (WINDII) on the NASA Upper Atmosphere Research Satellite (UARS), through Doppler wavelength shifts of the O(1S) atomic oxygen dayglow emission at 557.7 nm. This wind wall was not always present, but when it was it always occurred at the same geographic longitude, around 300°E in the northern hemisphere and 150°E in the southern hemisphere. A subsequent study showed that these wind walls occurred during times of enhanced geomagnetic disturbance, indicated by the ap index, and that the wind fields corresponded closely with those predicted by the WACCM-X model. Additional information on the wind wall and its temporal behavior could be provided by simultaneous observations from a ground-based instrument, located at the appropriate latitude and longitude. It proved possible to obtain a few WINDII observations made early in the UARS mission coincident with a Super Dual Auroral Radar Network (SuperDARN) station, and the results of these comparisons, together with data provided by the WACCM-X model are presented and discussed. The comparison showed that for significant geomagnetic disturbances the neutral wind/plasma drift reversals occurred at the same longitude and the same Universal Time. •A high-latitude wind reversal occurs at specific longitudes in both hemispheres.•This neutral wind reversal is persistently seen by the Wind Imaging Interferometer.•A plasma flow reversal is seen by SuperDARN, although at somewhat lower latitudes.•Winds are shown as a function of longitude and the plasma flow as a function of time.•The reversals occur during geomagnetic disturbances, identified by increased ap.