Numerical modeling of the Bering Strait acoustical monitoring

This paper claims the importance of the acoustic tomography of the Bering Strait water masses and describes some approaches in this direction. The sound signals at the receiving array for the typical environment conditions in Bering Strait are calculated by the pseudodifferential parabolic equation technique. The numerical linear tomographic scheme is developed to reconstruct the range-averaged sound-speed profile (SSP) variations with respect to particular reference (SSP) (and corresponding temperature and flux heat variations) on the basis of available data on induced travel times perturbations of normal modes in the range-dependent shallow-water waveguide. The modal travel times are associated with the several sequentional temporal locations of clear-cut envelope amplitude peaks of sound field at receiver array due to emitted broadband impulse signal. The above scheme takes into account the influence of the rough absorbing layered bottom and may be treated as the extention of pertinent scheme, derived by E.C. Shang (1989) for deep-sea case. The numerical simulation results demonstrate the good quality estimates of the range-averaged SSP variations with the acceptable r.m.s. error.