Abstract Using observations from a meteor radar chain, the Aura satellite, and reanalysis data, this study investigates the characteristics of quasi‐5‐day waves (Q5DWs) in the mesosphere and lower thermosphere (MLT) region of the Northern Hemisphere during the January 2021 Arctic sudden stratospheric warming (SSW) event. After the SSW onset, westward‐propagating Q5DWs were detected in the MLT region at Mohe (53.5°N), Beijing (40.3°N), Wuhan (30.5°N), and Ledong (18.3°N). Hough function calculation and satellite observations reveal that the Q5DWs observed in meteor radar winds at Mohe and Beijing consist of both westward wavenumber 1 (W1) and westward wavenumber 2 (W2) components, whereas the W1 component dominates at Wuhan and Ledong. The key findings of this study include: (a) both meteor radar and satellite observations identified the weakest Q5DW activity at low latitudes during the SSW event, and (b) in addition to a mesospheric wave source for W1 and W2 components around 55°N, an additional mesospheric wave source for the W1 component around 35°N was identified, likely contributing to its broader latitudinal coverage compared to the W2 component. These results offer valuable insights into the latitudinal evolution of Q5DWs in the MLT region during SSW events.
Bao et al. (Fri,) studied this question.