Stratospheric influence on MLT over mid-latitudes in winter by Fabry-Perot interferometer data

Abstract. In this paper, we study the response of the mesosphere and lower thermosphere (MLT) to sudden stratospheric warmings (SSWs) and the activity of stationary planetary waves (SPWs). We observe the 557.7-nm optical emission for retrieve the MLT wind, temperature with the Fabry-Perot interferometer (FPI) that has no analogues in Russia. The FPI is located at the mid-latitudes of Eastern Siberia within the Tory Observatory (TOR) at the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences (ISTP SB RAS, 51.8N, 103.1E). Regular interferometer monitoring started in Dec 2016. Here, we address the temporal variations in the 557.7-nm emission intensity, as well as the variations in wind, temperature, and their variability obtained by using the line parameters measurement during the 2016–2020 winters. Both SSWs and SPWs appear to have equally strong effects in the upper atmosphere. When the 557.7-nm emission decreases due to some influences from below (SSWs or SPWs), the temperature variation observed by using this line and the temperature itself increase significantly. The zonal wind dispersion does not show significant SPW- and SSW-correlated variations, but the dominant zonal wind reverses during major SSW events the same as the averaged zonal wind at 60N in the stratosphere does without significant delays.