Mitra, G.G.MitraGuharay, A.A.GuharayConte, J. F.J. F.ConteChau, J. L.J. L.Chau2025-08-312025-08-312023-10-1610.1029/2023GL1047562-s2.0-85173571807https://d8.irins.org/handle/IITG2025/26602Atmospheric tides and associated dynamics during two major boreal sudden stratospheric warmings (SSWs) have been investigated. The evolutionary Lomb Scargle and wavelet spectral analysis of specular meteor radar (SMR)-derived hourly winds reveal evidence of non-linear interactions between the semidiurnal solar tide and the quasi-20-day wave (Q20dw) during SSWs. The zonal wavenumber (ZWN) diagnosis indicates possible non-linear interaction between the dominant semidiurnal migrating tide (SW2) and zonally symmetric 20-day wave (20dw0) component, producing the secondary waves. The non-linear interaction between the ZWN 2 component of stationary planetary wave (SPW2) and westward propagating 20-day wave (20dwW2) in the stratosphere seems crucial to produce the 20dw0. As observed in the SMR-derived wind spectra, the excited 20dw0 possibly interacts non-linearly with SW2 to generate secondary waves. Therefore, the present study provides the first observational evidence of a two-step non-linear interaction associated with zonally symmetric planetary waves during major SSWs.truemiddle atmosphere | non-linear interaction | planetary waves | sudden stratospheric warming | tidesArticlehttps://onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2023GL1047561944800716 October 20232e2023GL104756arJournal2