OBUKHOV Institute of Atmospheric Physics RAS
«INFRASOUND PROPAGATION IN THE ATMOSPHERE: THEORY AND THE EXPERIMENT»
Authors: Sergey Kulichkov, Obukhov Institute of Atmospheric Physics RAS, Pyzhevsky 3, Moscow, 119017, RUSSIA
The problem of study long-range infrasound propagation in the atmosphere by theoretical and experimental methods are discussed. The ray theory, theory of nonlinear acoustic and the method of parabolic equation code to theoretical study of infrasound waves in the atmosphere are used.
The surface explosions and volcano eruptions are suggested as the sources of acoustic pulses. The IMS data and the data obtained on other infrasound stations were analyzed for the different events. It was observed that nonlinear effects are sufficiently change the amplitude and dominant periods of infrasound signals at the long distances from the pulsed sources. It was obtained that the effects of partial reflection of infrasound waves from the layered atmospheric structures in the middle atmosphere are the main source mechanism to penetration of infrasound in tha zone of acoustic shadow at the long distances from the pulsed sources. The problem of application of infrasound data to study temperature and wind velocity structure in the middle atmosphere are discussed. The effective sound speed profiles were obtained. For the first time the parameters of the fine-scale layered structure of wind velocity and temperature have been estimated in the stratosphere. It is important to note that the estimates of the vertical gradients of the effective sound speed in the upper stratosphere and lower thermosphere are not available from other remote sensing methods (radars, lidars). The future prospective for using the infrasound monitoring system data is outlined.