Characterization of the internal waves and its effect on signal propagation in the Adventure Bank area

During the Advent‐99 experiment, which took place in the Sicily Strait in May, 1999, multitone (in the band 200–1500 Hz) narrow‐band signals were transmitted from a bottom‐mounted tower and received on a 64 phone line array (VLA) covering the water column; the water depth was 80 m. Data at a source–receiver range of 10 km will be presented and modeled using an internal wave model. A CTD chain containing 48 CTDs on a vertical string was towed continuously during the acoustic experiments between the source and VLA, yielding a time‐evolving sound speed profile between the source and receiver. From that the average buoyancy frequency and sound speed profile were determined as a function of range. Internal‐wave‐mode depth functions were calculated using the measured buoyancy profiles. Internal‐waves‐mode amplitudes were determined from the eigenvalues of the sound speed covariance matrix for the lowest 5 modes. Internal‐wave‐frequency spectrum has the typical 2‐power dependence as in the Garrett–Munk model. Th...