Group of Atmospheric Acoustics

headed by Dr. Sergei L Odintsov

Investigations

• Investigation of acoustic wave transfer in the randomly inhomogeneous stratified atmosphere
• Development of methods and technical facilities for acoustic diagnostics of the atmospheric boundary layer
• Development of mathematical methods and algorithms for processing of random signals and fields
• Investigation of dynamic processes in the atmospheric boundary layer
• Development of methods and solution of problems of shortwave radiation transfer in inhomogeneous clouds, mesoscale cloud fields with random geometry, and the clear atmosphere

Investigation of acoustic wave transfer in the randomly inhomogeneous stratified atmosphere

Propagation of acoustic waves in the free atmosphere and along near-surface paths

• Investigation of the amplitude-phase characteristics of sound waves in the randomly inhomogeneous stratified atmosphere, including the study of coherence in the longitudinal and transversal directions of signal propagation.
• Study of the Doppler effect in inhomogeneous moving media.
• Investigation of sound propagation along near-surface paths with different ranges, signal frequencies, and classes of atmospheric stability.
• Solution of the problem of sound source bearing under the conditions of the randomly inhomogeneous stratified moving atmosphere.

Investigation of nonlinear effects accompanying propagation of acoustic waves

• Theoretical analysis of nonlinear effects in moving random media.
• Experimental investigations of nonlinear effects accompanying operation of powerful sodars.

Development of methods and technical facilities for acoustic diagnostics of the atmospheric boundary layer

Technical facilities:

• Remote sensing facilities: VOLNA-3 sodar", MAL-2 sodar
• Facilities for local measurements of atmospheric parameters: certified METEO-2 ultrasonic meter of atmospheric temperature and wind
• Standard meters of sound fields
• Three-channel multifrequency sodar with the capability of using bistatic schemes for sensing of atmospheric parameters (under development)

Objects of investigation:

• Wind
  • vertical and temporal structure of different components of the total wind in different geophysical situations
  • statistical moments (up to the fourth one inclusive) of wind velocity components
  • diagnostics of the turbulent wind velocity component: turbulence intensity and anisotropy
  • correlations of the wind field in the atmospheric boundary layer as judged from acoustic sounding data
  • coherent structures in random wind flow
• Structure of the turbulent component of the temperature field
  • profiling of the structure characteristic C_T² in the atmospheric boundary layer
  • structure diagnostics at different types of stratification
• Internal gravitational waves: detection and diagnostics of basic parameters.
• Turbulent heat and momentum fluxes: study of the possibility of using the acoustic sounding data for retrieval of the vertical and temporal profiles of turbulent heat and momentum fluxes.
• Precipitations: theoretical and experimental study of precipitation structure in the atmospheric surface layer.
• Sounding noise: correlation and spectral analysis of external noise, methods for compensation and active interference blanking.

Development of mathematical methods and algorithms for signal processing

• Spectral analysis of sodar signals.
• Spectral analysis of temporal dynamics of wind velocity.
• Analysis of distribution moments of different wind components .
• Analysis of distributions and their moments when studying teh amplitude of sodar signals.
• Analysis of multichannel data flow.
• Analysis of data in measurements of oscillatory processes of various origin.

Main Results

• New experimental and theoretical results on the interaction of acoustic radiation with the atmosphere have been obtained, and new technical facilities has been developed for the remote (sodars) and local (ultrasonic weather station) acoustic diagnostics of the lower atmosphere.
• The transformation of the acoustic field under the effect of local-scale coherent structures in the wind velocity field, which is ignored by the modern sound propagation theory, has been revealed from the analysis of experimental results.
• Regularities have been found in the generation of acoustic signals at the interaction of optical radiation of different intensities and wavelengths with gas, liquid, and solid atmospheric impurities. Investigations with the use of developed facilities for the acoustic diagnostics revealed unique data on the structure of the wind flow in the planetary boundary layer, in particular, in urban regions and near the Lake Baikal shoreline.
• Our technical and methodical results are used by institutes of the Russian Academy of Sciences and its Siberian Branch, by ecological monitoring institutions, and at territories of industrial enterprises.
• A model of the transfer of short-wavelength radiation has been developed. It ensures the correct calculation of spectral fluxes and brightness fields under various atmospheric conditions, including spatially inhomogeneous and stochastic cloudiness. The computational scheme for the consideration of molecular absorption based on the method of k-distributions allows the use of novel spectroscopic data, the information on concentrations of atmospheric gases and the instrument function in computations. The reliability of simulation results has been confirmed by the comparison with calculations within the framework of the international Intercomparison of 3D Radiation Codes and by results of testing with line-by-line calculations and experimental data.

Personnel

1. Valerii A Fedorov, adv.engineer, phone: +7 3822 491-463, E-mail: fva21@iao.ru
2. Vladimir A Gladkikh, senior staff scientist, phone: +7 3822 491-421, E-mail: glvl@iao.ru
3. Andrei P Kamardin, staff scientist, phone: +7 3822 491-111 + 10-96, E-mail: kap136@iao.ru
4. Tamara Yu Malkina, technician
5. Alina A Mamysheva, engineer, phone: +7 3822 492-256, E-mail: alina434@iao.ru
6. Irina V Nevzorova, leader programmer, phone: +7 3822 491-463, E-mail: nevzorova@iao.ru
7. Sergei L Odintsov, leader staff scientist, Dr., phone: +7 3822 491-573, E-mail: odintsov@iao.ru