Physics of auroral phenomena : proceedings of the 38th annual seminar, Apatity, 2-6 march, 2015 / [ed. board: A. G. Yahnin, N. V. Semenova]. - Апатиты : Издательство Кольского научного центра РАН, 2015. - 189 с. : ил., табл.

*P hysics o f Auroral P henom ena", Proc. XXXVIII A n n ual Sem inar, A patity, pp. 177-180, 2 0 1 5 © Kola Science Centre, Russian Academy o f Science, 2015 Polar Geophysical Institute In memory o fM.I. Beloglazov GROUND-BASED MICROWAVE MONITORING OF OZONE IN THE MIDDLE ATMOSPHERE ABOVE St. PETERSBURG AND TOMSK IN THE WINTER 2013-2014 Y.Y. Kulikov, V.G. Ryskin (Institute o f Applied Physics RAS, Nizhny Novgorod) D.A. Bochkovskii, V.N. Marichev (Institute o f Atmospheric Optics Siberian Branch RAS, Tomsk) A.V. Poberovskiy, Yu.M. Timofeev (St.Petersburg State University, Saint Petersburg) Introduction Recently to study the nature of variation of ozone and temperature in the middle atmosphere are widely used means of microwave remote sensing as orbital and ground-based [1, 2]. Changes in ozone have a significant impact on radiation and thermal regime of the atmosphere. To interpret the results of these measurements, it is necessary to draw data on the temperature dependence of the height that can be presented in the form of zonal models [3], and in the form of measured values, for example, aerological or rocket sounding data. Very successful are the measurement results of vertical temperature profile by lidars which are located on the Earth's surface [4, 5]. It should be emphasized that the strongest impact of changes in the temperature profile on the results of microwave observations of ozone in the middle atmosphere will occur during the so-called sudden stratospheric warming [2]. Therefore, simultaneous measurement of the real variations of ozone and temperature occurring in the middle atmosphere can give the opportunity to explore the dynamic processes during modification of atmospheric circulation. In this paper we present the results of measurements of ozone in the middle atmosphere in St. Petersburg (60°N, 30°E) and Tomsk (56°N, 85°E) using the same microwave ozonemeters during stratospheric warming in the winter of 2013-2014. Very important here is the use the same methods of observation and estimate of the vertical distribution ozone in the middle atmosphere. These results were compared with satellite data (OMI/Aura) on the total ozone content (TOC) and the altitude profiles of ozone and temperature in the layer of 20-60 km (MLS/Aura). Microwave ground-based equipment used in the experiment Method ground-based microwave radiometry is based on measurements of thermal atmospheric radiation in vicinity the ozone line in the range of millimeter and submillimeter waves. Microwave observations are weakly dependent on weather conditions and the presence of atmospheric aerosols, and this is an advantage compared with observations in the optical and infrared wavelength ranges. In addition, the microwave ozone observations can run around the clock. In recent years it is managed to make a significant step forward towards the creation of a new generation of mobile microwave spectrometers [6]. The device consists of an uncooled heterodyne receiver tuned to a fixed frequency 110836.04 MHz corresponding to a rotational transition of ozone molecules 60.6~ 6I5, and multichannel spectrum analyzer. In front of receiver is a module that includes an antenna (scalar horn) and a switch to calibrate accepted intensity of atmospheric ozone line radiation. The beam width (by level -3 dB) of the horn antenna is 5.4°. The SSB noise temperature of the receiver is 2500 K. The SSB receive mode is provided by evanescent filter with direct losses of 0.5 dB and the suppression of the image channel of more than 20 dB. The spectrum analyzer consists of 31 filter with a variable bandwidth from 1 MHz to 10 MHz and a full analysis bandwidth of 240 MHz. The parameters of the device allow to measure a spectrum of the emission ozone line for time about 15 min with a precision of ~ 2%. Measurement of the spectra of thermal radiation is performed by a method of calibration for two "black body" loads that are at the boiling point of liquid nitrogen and at ambient temperature. Information about the content of the 0 3 is contained in the measured radio emission spectrum of the middle atmosphere. Using the inversion of the obtained spectra it is possible to obtain data on the vertical . distribution of ozone (VDO) in the atmosphere. The criterion of the accuracy of inverse problem solution is the best fit ozone spectral lines calculated by the retrieved profile of the 0 3 concentration to the original experimental spectrum. The error of estimating the VDO on the measured spectra by above described device does not exceed 20%. The results of observations and discussion Fig. 1 shows the ozone variation in November-March, 2013-2014 over Peterhof (left panel) and in December- January 2013-2014 over Tomsk (right panel). In the left panel, the crosses are the data on total ozone content (TOC), which were obtained onboard device OMI/Aura [7]. The average value of the TOC for the entire observation period amounted to (323±4) DU. Since the February 11 well a noticeable increase in the TOC, which lasted for 10 days with the average value (413±8) DU. Maximum TOC 454 DU was marked on Februaryl7, 2014. The total ozone values before and after the disturbance are equal to (313±5) DU and (308+6) DU respectively. In addition, it can note a short-term increase in TOC on March 24 with the average value (388±7) DU. At the bottom left panel of Fig. 177