### ASA 125th Meeting Ottawa 1993 May

## 5aPA6. A numerical study of sound propagation through a turbulent
atmosphere.

**Daniel Juve
**

**
Philippe Blanc-Benon
**

**
Patrick Chevret
**

**
**
*Dept. of Acoust., Ecole Centrale de Lyon, 36 Av. Guy de Collongue, 69131
Ecully Cedex, France
*

*
*
A numerical simulation of the effect of turbulent conditions on the
propagation of acoustic waves in the atmosphere has been developed. The
turbulence is represented as a set of realizations of a random field generated
by a limited number of random Fourier modes [Karweit et al., J. Acoust. Soc.
Am. 89, 52--62 (1991)]. Through each individual realization, the acoustic
pressure field is computed in the parabolic approximation. Ensemble averaging
is thus performed to obtain the statistical properties of the field: mean
level, standard deviation of the fluctuations, probability density functions,
etc. Results will be given in particular for upward refracting conditions, when
turbulence diffracts sound into the deterministic shadow zone.