Variations in the Thermosphere During the 2018 SSW Event at Beijing and Wuhan

Abstract

Daytime thermospheric responses to the 2018 sudden stratospheric warming (SSW) are investigated in this study. The method proposed by Li et al. (2023), https://doi.org/10.1029/2022ja030988 for deriving exospheric temperature (Tex) from electron density (Ne) profiles was employed. Reliability of this method was verified through comparisons with observations from incoherent scatter radar and the Swarm-C satellite, showing Tex relative deviations within ±2% at most cases. At Beijing, SSW effects manifested as cooling, with a reduction in average Tex by −1–−17 K and average neutral density decreasing by 3%–15% compared to non-SSW. Differently, at Wuhan, SSW effects exhibited semi-diurnal-like variations consistent with previous studies. Average Tex increased by up to 13 and 9 K, and average neutral density increased by up to ∼13% and ∼5% near the dawn and dusk sectors, respectively. Decreases of up to −15 K and ∼−12% were observed near the noon sector. These distinct characteristics, including latitude-dependence and semi-diurnal-like variations, highlight the role of SSW in modulating the thermosphere, providing an opportunity to better understand the vertical coupling between different atmospheric regions.