FY 2002

Calcium carbonate dissolution in the Pacific Ocean

Feely, R.A., C.L. Sabine, K. Lee, F.J. Millero, M.F. Lamb, J.L. Bullister, R.M. Key, R. Wanninkhof, T.-H. Peng, and A. Kozyr

In Sixth International Carbon Dioxide Conference, Sendai, Japan,, 1–5 October 2001, 617–620 (2001)

As a part of the U.S. JGOFS synthesis and modeling project, researchers have been working to synthesize the WOCE/JGOFS/DOE/NOAA global CO survey data to better understand carbon cycling processes in the oceans. Working with international investigators we have compiled a Pacific Ocean data set with over 35,000 unique sample locations analyzed for at least two carbon species, oxygen, nutrient, CFC tracers, and hydrographic parameters. These data are being used to determine the rates of in-situ CaCO dissolution in the water column of the Pacific Ocean. Calcium carbonate dissolution rates (ranging from about 0.05-1.1 µmol kg yr) are observed in the intermediate and deepwater depths beginning near the aragonite saturation horizon. Within the North Pacific Intermediate Water (depth range: 400-800 m), CaCO dissolution rates are more than 7 times faster than observed in mid- and deepwater depths (average = 0.051 µmol kg yr) of the North Pacific.