AN OVERVIEW OF THE 1995 SWARM SHALLOW-WATER INTERNAL WAVE ACOUSTIC SCATTERING EXPERIMENT

An overview is given of the July-August 1995 SWARM shallow-water inter nal wave acoustic scattering experiment. This experiment studied both acoustic propagation through and scattering by the linear and nonlinea r internal waves found on the Mid-Atlantic Eight continental shelf, as well as the physical oceanography of the internal wavefield, In order that our goal of explaining the nature of the acoustic scattering sho uld not be hindered by incomplete environmental knowledge, numerous in struments, both ship-deployed and moored, measured the acoustics, geop hysics, and oceanography. In this paper, we show some of the results f rom the first year's analysis of the environmental and acoustic data, The environmental measurements, which are a key input to the analyses of the acoustic data, are given slightly more emphasis at this point i n time, Some of the more interesting oceanographic, geophysical, and a coustical results we present here are: evidence for the dominance of t he lee-wave mechanism for soliton production, evidence for the ''solib ore internal tide,'' the ''dnoidal wave'' description of solitons, the inversion of chirp sonar data for bottom properties, propagation loss extraction from air-gun data, and the intensity and travel-time fluct uations seen in propagating acoustic normal modes. Directions for futu re research are outlined.