Acoustic Remote Sensing of Large-Scale Temperature Variability in the

North Pacific OceanPeter F. Worcester, Bruce D. Cornuelle,Matthew A. Dzieciuch, Walter H. Munk

Scripps Institution of Oceanography, University of California, San Diego

Brian D. Dushaw, Bruce M. Howe,James A. Mercer, Robert C. Spindel

Applied Physics Laboratory, University of WashingtonDimitris Menemenlis

Jet Propulsion Laboratory, NASADetlef Stammer

Institut für Meereskunde, Universität Hamburg

AGU Ocean Sciences MeetingPortland, Oregon, 26-30 January 2004

Acoustic Thermometry of Ocean Climate: Goals

Determine the precision with which acoustic methods can measure large-scale changes in ocean temperature

Determine what effects, if any, the acoustic transmissions have on marine mammals and other marine life

North Pacific Acoustic Laboratory

North Pacific Acoustic Laboratory: Goals

To perform the second phase of research on the feasibility and value of large-scale acoustic thermometry

To study the behavior of sound transmissions in the ocean over long distances

To conduct studies on the possible long-term effects from the sound transmissions on marine life

ECCO OGCM: SIO

Summary Long-term trends in large-scale ocean temperature are

easily visible in the acoustic time series Travel times can now be readily computed from

OGCMs for comparison with acoustic data Travel times have good signal-to-noise ratios for

differences between models Assimilation of travel times into OGCMs is needed to

objectively assess the value of acoustic methods OGCM parallelization makes non-local observations

more complicated to assimilate using adjoint methods