Matthew A. Dzieciuch
Scripps Inst. of Oceanog., IGPP-0225, UCSD, La Jolla, CA 92093
Anthropogenic CO2 in the atmosphere is expected to result in increased ocean heating. The output of a coupled ocean-atmosphere general circulation model was used to simulate to expected climate change scenario. The model was run with no CO2 increase and with CO2 doubling. The spatial properties of the CO2 signal are nonuniform and show that heating is not confined to the ocean surface. The ambient climate variability shows a different spatial structure that is more emphasized at the surface. The GCM output was then used as an input to an acoustic propagation model. The acoustic time series can then be analyzed for climatic trends. The control run is used to estimate the ambient noise processes on long-term scales. Maps of the anthropogenic signal to the ambient noise ratio of the climate system can then be constructed. Acoustic thermometry measures integrals of heat content through these maps. A network of sources and receivers can then be designed to efficiently monitor anthropogenic climate change. Work is in progress to compare the efficiency of different measurement systems such as satellite altimeters, drifters, and traditional measurements to that of acoustic thermometry.