On the longitudinal structure of the transient day-to-day variation of the semidiurnal tide in the mid-latitude lower thermosphere

CC BY 3.0 UnportedMerzlyakov, E.G.Portnyagin, Yu.I.Jacobi, C.Mitchell, N.J.Muller, H.G.Manson, A.H.Fachrutdinova, A.N.Singer, W.Hoffmann, P.2018-03-092019-06-282001https://doi.org/10.34657/1613https://oa.tib.eu/renate/handle/123456789/4075The longitudinal structure of the day-to-day variations of semidiurnal tide amplitudes is analysed based on coordinated mesosphere/lower thermosphere wind measurements at several stations during three winter campaigns. Possible excitation sources of these variations are discussed. Special attention is given to a nonlinear interaction between the semidiurnal tide and the day-to-day mean wind variations. Data processing includes the S-transform analysis which takes into account transient behaviour of secondary waves. It is shown that strong tidal modulations appear during a stratospheric warming and may be caused by aperiodic mean wind variations during this event.application/pdfenghttps://creativecommons.org/licenses/by/3.0/530Meteorology and atmospheric dynamics (middle atmosphere dynamicswaves and tides)On the longitudinal structure of the transient day-to-day variation of the semidiurnal tide in the mid-latitude lower thermosphere - I. Winter seasonArticle