Variations of Low-latitude Thermospheric Winds and Temperature during the 2020/2021 Major Sudden Stratospheric Warming as Observed by ICON and GOLD Satellites

Using ICON and GOLD satellite observations, the response of the thermospheric daytime horizontal winds and neutral temperature to the 2020/2021 major sudden stratospheric warming (SSW) is studied at low- to middle latitudes (0° - 40°N). Comparison with observations during the non-SSW winter of 2019/2020 and the pre-SSW period (December 2020) clearly demonstrates the SSW-induced changes. The northward and westward thermospheric winds are enhanced during the warming event, while temperature around 150 km drops by up about 50 K compared to the pre-SSW phase. Changes in the horizontal circulation during the SSW can generate upwelling at low-latitudes, which can contribute to the adiabatic cooling of the low-latitude thermosphere. The observed changes during the major SSW are a manifestation of long-range vertical coupling in the atmosphere.