Thermospheric Neutral Winds Above the Oukaimeden Observatory: Effects of Geomagnetic Activity

International audienceIn the context of space weather, we investigate the effect of geomagnetic activity on Earth's thermosphere above the Oukaimeden Observatory in Morocco (geographic coordinates: 31.206°N, 7.866°W; magnetic latitude: 22.77°N) over 3 years from 2014 to 2016. The observatory is equipped with a Fabry-Perot interferometer (FPI) that provides measurements of thermospheric wind speed. In this study 41 disturbed nights (with SYM-H ≤ -50 nT, Kp ≥ 5) were identified and analyzed. We have characterized the meridional and zonal winds variability and dependence on the solar cycle, during both quiet and disturbed conditions. We have classified the storm time meridional neutral winds into three types of variation. The first type is characterized by traveling atmospheric disturbance (TAD)-induced circulation: the first TAD coming from the north and the second TAD being transequatorial, coming from the south. This type of storm with TAD-induced circulation accounts for 59% of the cases. The second type exhibits only slight discrepancies between the disturbed and quiet night flows. These cases account for 33% of the cases. The third type is characterized by the transequatorial wind in whole the night. This last type accounts for 8% of the cases. Finally, we apply a superposed epoch analysis method on the FPI data, and the effect of each phase of the geomagnetic storm on the wind flow and vertical total electron content VTEC has been quantified