ИСТИНА

We present the results of studying effects the 2013 January major Sudden Stratospheric Warming (SSW) on the Mesosphere and Low Thermosphere (MLT) at two longitudinally spaced mid-latitude sites. For the analyses, the data on the OH(6-2), 834.0 nm emission intensity and rotational temperature were used. These data were obtained through spectrometric measurements at the Geophysical Observatory of the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences (51.8°N, 103.1°E, Tory), and at the Zvenigorod Station at the Obukhov Institute of Atmospheric Physics of the Russian Academy of Sciences (55.7°N, 36.8 E°). By using the data of the OH emission measurements and photochemical model of the OH radiation, we calculated the concentration of atomic oxygen and its variations. We found, that the response of the mesopause characteristics for two longitudinally spaced mid-latitude sites essentially differs. Thus, from the Tory Station data, the maximal increase in the OH emission intensity and in the concentration [O] occurred during the SSW evolution, whereas, from the Zvenigorod Station data, the OH emission intensity and [O] intensified at the SSW recovery phase. Numerical modeling by using the Middle and Upper Atmosphere Model (MUAM) revealed, that that effect may probably be caused by longitudinal differences in the diurnal variation in the vertical wind at the mesopause heights over the indicated sites during the SSW. The study was funded by RFBR and MOST according to the Russian-Taiwanese joint research project 18-55-52006 MHT_a. The experimental data recorded by the equipment of Center for Common Use «Angara» http://ckp-rf.ru/ckp/3056/ at the ISTP SB RAS (Tory Station) obtained within the Basic Research program II.16 were used.