CHANGES IN THE MIDDLE AND UPPER ATMOSPHERE PARAMETERS DURING THE JANUARY 2013 SUDDEN STRATOSPHERIC WARMING

We present the results of complex observations of various parameters of the middle and upper atmosphere over Siberia in December 2012 - January 2013, during a major sudden stratospheric warming (SSW) event. We analyze variations in ozone concentration from microwave measurements, in stratosphere and lower mesosphere temperatures from lidar and satellite measurements, in the F2-layer critical frequency (f(o)F2), in the total electron content (TEC), as well as in the ratio of concentrations of atomic oxygen to molecular nitrogen (O/N-2) in the thermosphere. To interpret the observed disturbances in the upper atmosphere, the experimental measurements are compared with the results of model calculations obtained with the Global Self-Consistent Model of Thermosphere-Ionosphere-Protonosphere (GSM TIP). The response of the upper atmosphere to the SSW event is shown to be a decrease in f(o)F2 and TEC during the evolution of the warming event and a prolonged increase in O/N-2, f(o)F2, and TEC after the SSW maximum. For the first time, we observe the relation between the increase in stratospheric ozone, thermospheric O/N-2, and ionospheric electron density for a fairly long time (up to 20 days) after the SSW maximum at midlatitudes.