Physics of auroral phenomena : proceedings of the 35th Annual seminar, Apatity, 28 Februaru – 02 March, 2012 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2012. - 187 с. : ил., табл.

Acoustic effects o fan underwater explosion in the D region ofthe polar ionosphere 12.08.2000 7:28:27 7:30:42 •s s' UT, hrs UT. hrs Fig. 3. Variations of amplitude of reflections and its wavelet spectrum during the underwater explosion. Fig. 2. Magnetograms of the Я-component received at Tumanny and its wavelet spectrum during the underwater explosion. Время UT, hrs Г200 7\ min Fig. 4. a) fluctuations of the total electron content in the mesosphere on 12 August 2000 from 07:20 till 08:20 UT, b) their wavelet spectrum, and c) their Fourier spectrum. At the same time, the amplitude of S A 'te c exceeds the level of background fluctuations at least in 2-4 times that indicates about essential influence of the explosion on the lower ionosphere. The first significant disturbances of TEC have arisen in 10 minutes after the explosion. It was observed three splashes ШТЕС during 20 minutes. Phase speed of quasi-periodic disturbances (300 m/s) is close to speed of sound at the heights of the D region of the ionosphere. In Figure 4c it is visible, that the underwater explosion leads to generation or amplification of infrasonic waves with the periods from 2 till 4 minutes and IGW with the periods of 6, 8 and 16 minutes. An underwater explosion forms a bubble of hot gases and pressure inside the bubble is much higher, than in the environment The gas bubble in process of rise to the surface of water quickly extends and forms in water a shock wave An output of the shock wave to the surface of water and the subsequent formation of a water column or a sultan and then its rise and destruction during break of products of explosion into the atmosphere force neutral gas 121