NESCAFE-pilot

This cruise is part of the ONR Task Force Ocean Department Research Initiative. The experiment is meant to characterize the highly variable acoustic propagation that is observed in the area around the Atlantis II seamounts The variability is manifested in the acoustic impulse responses and the ambient soundscape and is caused by oceanographic and atmospheric processes as well as complex seafloor topography. The main challenge of this experiment will be to see if the acoustic arrival pattern of the observations is predictable given some base of information. That is to say: can we identify the ray paths and ducted energy based upon the available environmental information? The environmental information can come from climatology, ocean models (such as HYCOM), or local observations. If the paths or ducted modes can be identified we seek to answer two further questions: 1) Can the acoustic observations be used to infer properties of the sound-speed profiles? and 2) Can we predict the statistics of the arrivals? (such as the transmission loss distribution and the space-time coherence.) A month-long pilot cruise is being planned with the mooring deployment in the beginning and recovery at the end. During the middle of the cruise, other groups will be collecting environmental information. These groups include M. Alford (SIO) with a fast-CTD to collect water column information, J. Miller (URI) with OBSs to characterize sea-bottom properties, and Megan Ballard (ARL-UT) with seafloor hydrophone systems (AMARS) to observe scattering from the seamount. Y.T. Lin (WHOI) will also test his acoustic mooring.