Physics of auroral phenomena : proceedings of the 33rd Annual seminar, Apatity, 02 - 05 March, 2010 / [ed.: A.G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2011. - 206 с. : ил.

INFLUENCE OF HF POWERFUL WAVES ON THE OZONE CONTENT IN THE EARTH’S ATMOSPHERE Y.Y. Kulikov1, V.L. Frolov2, V.M. D em kin1, G.P. Kom rakov2, A .A . K rasiln ikov1, V .G . R y sk in1 1 Institute o fApplied Physics, Nizhny Novgorod, Russia 2 Radiophysical Research Institute, Nizhny Novgorod, Russia Abstract. We present some results of microwave measurements o f ozone number density variations in the mesosphere (in the ionospheric D-region at altitudes of ~ 60 km) under conditions when the ionosphere was pumped by high-frequency powerful radio waves radiated by the Sura heating facility, which is located near Nizhny Novgorod, Russia (coordinates: 56.15°N, 46.13°E). Determination of the ozone number density in the upper atmosphere was made using the method of the ground-based microwave radiometry, which is based on spectral measurements of thermal atmospheric emissions detected in the frequency range of the ozone radiation. The decrease of microwave emission intensity for the ozone line in HF-pumped atmosphere was first revealed. Experimental arrangements “P hysics o f Auroral P henom ena ”, Proc. XXXIII A n n u a l Sem inar, A patity, pp. 1 7 4 -1 7 7 , 2011 © Kola Science Centre, Russian Academy of Science, 2011 Polar Geophysical Institute Experiments were arranged in the following manner. The Sura facility radiated X-mode powerful radio waves at the pump wave (PW) frequency of 4300 kHz with the effective radiated power Pc{( = 80 MW. The pump beam was tilted 12° to the south from the zenith. In this direction it was directed by a mirror the beam of a mobile microwave instrument used to observe the 6, .5 to 60.6 transition o f ozone at 110.836 GHz. The instrument for emission intensity measurements (see Fig. 1) is comprised of a microwave heterodyne receiver and a multichannel spectrometer. Ozone line spectra were measured with the time resolution o f 15 min by the use of the method of absolute calibration of registered emission intensity by means of two radiation standards, one of which was at the temperature of background air, whereas the second one was at the temperature of the liquid nitrogen boiling-point. To receive the emissions a ridged horn was used with half-power beam width of 5.4°, which is a few times smaller than the Sura antenna beam width o f ~ 15°. Characteristics of the microwave instrument (ozonemeter) are the following: the noise temperature is of 2500 K; the bandwidth of analysis is o f 240 MHz; the spectral resolution is of 1 to 10 MHz; the number of spectral channels is of 32 [1,2]. Fig. 1. The view of the microwave ozonemeter used in the measurements (twenty-four-hour observations) from March 14 till March 19,2009. 174