Temporal evolution of the temperature, zonal wind, and density during the 2021 SSW

(a) Zonal mean temperature gradient between the North Pole and 60° N and (b) zonal mean zonal winds over 60° N from the MERRA-2 data. (c) Zonal temperature and (d) the relative density deviation between that during the 2021 Sudden Stratospheric Warming event and the climatology over 70° N from the MLS data. (e) Zonal temperature and (f) the relative density deviation between that during the SSW event and the winter average (December, January, and February) over 70° N from the FY-3C/GNOS data.