Acoustic thermometry of ocean climate. A description of the acoustic network

Abstract

The ATOC acoustic feasibility network became functional in December 1995 following the installation of an acoustic source on Pioneer Seamount approximately 50 nm off the coast of Northern California. The current effort is part of the Marine Mammal Research Program Pilot Study. This paper describes the acoustic network of sources and receivers, including the augmentations to be made in summer 1996. The network was designed to take advantage of existing hydrophone arrays, while providing for maximum coverage of the North Pacific by the acoustic paths. The acoustical receptions currently being obtained are processed to obtain ‘‘dot plots’’ which show the arrival times and arrival angles of acoustical energy above a chosen signal-to-noise ratio. The ‘‘dot plot’’ histories demonstrate stable ray arrivals (albeit with significant amplitude fluctuations) for even the longest propagation ranges of 5 Mm. [Work supported by the Strategic Environmental Research and Development Program through ARPA.]