Physics of auroral phenomena : proceedings of the 39th annual seminar, Apatity, 29 February-4 March, 2016 / [ed. board: N. V. Semenova, A. G. Yahnin]. - Апатиты : Издательство Кольского научного центра РАН, 2016. - 167 с. : ил., табл.

“Physics o f Auroral Phenomena". Proc. XXXIX Annual Seminar, A patity, pp. 101-103. 2 0 1 6 © Polar Geophysical Institute, 2016 Polar Geophysical Institute SIMULTANEOUS OBSERVATIONS OF GRAVITY WAVES IN AURORA AND BY PARTIAL REFLECTION RADAR V .C. Roldugin', S.M. Cherniakov2, A.V. Roldug in1 P o la r Geophysical Institute, 1A pa tity, 2Murmansk, Russia e-mails: rold_val@pgia.ru, sergeich@ pgi.ru A b stra c t. During aurora observations at the observatory Lovozero in certain cases the luminescence of the night sky had a wavy structure with the wavelengths of several tens kilometers and with the temporary periods about 15- 30 minutes. It allows assuming that they are caused by acoustic-gravity waves. For two cases comparisons with data of the radar of partial reflections in the observatory Tumanny have been carried out. Maxima of reflection amplitudes of the radar took place at the heights of 80-90 km and amplitudes at these heights had the periods similar to the periods of fluctuations of luminous intensity of the sky. 1. In tro d u c tio n In 1960 Hines had shown that gravity waves were the important atmospheric phenomenon [Hines, 1960] and intensive researches of this phenomenon including the use of optical methods have begun [Armstrong, 1982]. Optical registration of the waves in the ionosphere was carried out during the campaign ALOHA-93 on low latitudes by several researchers. So, in works of Taylor et al. [1995a, b] were presented results of photography of all-sky cameras in the OI emissions (557.7 nanometers), the doublet of sodium (589.2 nanometers) and the near infrared range of the OH hydroxyl emissions. These emissions have different mechanisms of excitement and emit at little different heights that allows to judge about dynamics of waves. The auroral origin of waves in these and similar works, of course, is excluded because of the near equatorial location of points of their observations. There are many data, which show that the certain class of the traveling ionospheric disturbances caused by the acoustic-gravity waves (AGW) has the origin in the auroral zone during its hyperactivity. The problem of generation of AGW by the auroral electrojet and the relative role of Joule heating and Lorentz force were theoretically considered in works [Chimonas, Hines, 1970; Francis, 1974, 1975]. In the article by Chimonas and Hines the authors have received an expression, which described the relative contribution of Joule heating and Lorentz force to generation of AGW from the auroral electrojet. Hunsucker [1977, 1982] has estimated the AGW parameters, using experimental data. In the series of experiments Wilson [1969a, 1969b, 1969c] has shown that the auroral arc at its supersonic movement was followed by a pressure wave, which could be recorded by experimental means. Chemouss et al. [2002] reported about a wave-like structure in aurora luminosity over Lovozero after a rocket launch in the Arkhangelsk region. It had the horizontal wavelength about of 35 - 40 km, the period about 3-4 min and propagation speed 180-240 km/s. For consideration of manifestation of gravity waves we have compared observations of independent measurements: the luminescence of the night sky and data p. , _ , , - . _u t of the radar. The luminescence intensity Figure 2. Temporary behavior of the f. tered amplitude of the data were obtajned b thj} camera > i“ rdinary wave (“P> and ,ts wavelet sPectrum (down) for the observatory Lovozero of the Polar 26.02.2012 Geophysical Institute (67.97° N, 35.02° E). 101