The Acoustic Thermometry of Ocean Climate (ATOC) Project: Towards depth-averaged temperature maps of the North Pacific Ocean

The ATOC Project has aquired trans-Pacific acoustic data from two acoustic sources: one located on Pioneer Seamount off the coast of California, the other located north of Kauai, Hawaii. Transmissions from these sources are detected by U.S. Navy SOSUS arrays located throughout the North Pacific. The time series of acoustic travel times from the Pioneer Seamount and Kauai transmissions are about 1 1/2 and 1 year long, respectively. Both time series have highly irregular sampling because of marine mammal protocols and temporary cable failures; the timeseries derived from the two acoustic sources overlap by about 75 days. These acoustic data are used to accurately estimate ocean temperature. The overlapping time series for the first time allow estimates of temperature maps of the North Pacific basin using long-range acoustics because the acoustic paths from these sources criss-cross the North Pacific. Maps of depth-averaged temperature of the North Pacific Ocean are derived using the time series collected through 1998.