English

Abstract

We present nighttime variation of thermospheric winds estimated from the Fabry-Perot interferometer (FPI) which was recently deployed at Abuja in Nigeria. These results apply to the thermosphere region around 250 km and were obtained during the period of weak solar activity with solar flux values generally below 70 s.f.u. The results presented cover three months, from October 2017 to December 2017. The high geomagnetic activity level zonal winds generally lag the low geomagnetic activity level winds. Low geomagnetic activity level wind speeds are maintained between 80 and 100 m/s. High activity zonal wind speeds revealed minimum speed values between 0030 LT to about 0330 LT. We also present comparison between our observations and the latest version of the horizontal wind model (HWM14). The model predicts are generally in good agreement with our zonal wind observations. Our limited data used in the investigation is likely responsible for the significant discrepancies observed in the meridional winds. Key words: Equatorial thermosphere, Low solar activity, thermospheric dynamics, meridional and zonal winds.