U.S. JGOFS SMP

U.S. JGOFS Synthesis & Modeling Project
Will Berelson William M. Balch Richard A. Feely Raymond Najjar Christopher L. Sabine Collaborator: Kitack Lee
Production and Dissolution of Calcium Carbonate in the Global Ocean: A synthesis and modeling project NSF
PROJECT DESCRIPTION:	The marine carbonate cycle is of major importance to the global carbon cycle, surface ocean light field, particle ballasting, and paleoceanography. Yet many uncertainties exist in our understanding of its budget. Not only are there large uncertainties in the quantification of the marine CaCO3 production and dissolution on the regional to global scales, but our understanding of the processes that regulate this budget is extremely primitive. A matter of direct relevance to the JGOFS Synthesis and Modeling Project is the fact that it is not currently possible to develop robust, predictive models of CaCO3 cycling in the sea, or evaluate the role CaCO3 plays in the overall global carbon cycle and how that role may change with future climate change. We propose to focus on 4 major objectives: Improving regional and global scale estimates of surface ocean PIC standing stocks and calcification rates. This will be achieved through (i) a synthesis of standing stock and calcification rate measurements and (ii) their extrapolation to larger spatial and temporal scales using satellite data. Improving regional and global scale estimates of surface CaCO3 export. This will be achieved by (i) constraining an ocean general circulation model (GCM) with the observed surface alkalinity distribution and by (ii) a synthesis of shallow sediment trap data. Improving regional and global scale estimates of shallow (100-1000 m) dissolution rates by (i) a technique that uses the relationship between alkalinity and chlorofluorocarbons, (ii) an evaluation of this technique using GCM output, (iii) assessing the importance of continental margin sediments as sources of alkalinity to the shallow ocean and (iv) a synthesis of sediment trap-derived dissolution rate measurements. Improving regional and global scale estimates of deep (>1000 m) dissolution rates by (i) a technique that uses the relationship between alkalinity and radiocarbon, (ii) an evaluation of this technique using GCM output, (iii) using an existing synthesis (by S. Honjo and R. Francois) of sediment trap-derived dissolution rates and (iv) a synthesis of sediment dissolution rate measurements. This is a collaborative proposal involving the efforts of 5 PI's-W. Balch (Bigelow Lab), W. Berelson (USC), R. Feely (NOAA-PMEL), R. Najjar (Penn State) and C. Sabine (U. Washington and NOAA-PMEL). These PI's have complementary expertise in areas of calcification, satellite algorithms, sediment trap interpretation, water column chemistry, global modeling and sediment geochemistry and propose to take a multi-disciplinary approach to understanding the modern global marine CaCO3 cycle. The PI's will work together, melding observations with models, to derive constraints on fluxes and inventories. These results will be used to develop basin-scale and global carbonate budgets with a particular emphasis on reducing the uncertainties in our understanding carbonate production, export, shallow and deep dissolution. K. Lee is also involved with this research and will be contributing on a consulting basis. Manuscripts on carbonate dissolution have already been submitted by D. Feely (Pacific ocean) and C. Sabine (Indian ocean). In the coming months we will be working on Atlantic ocean budgets and then an integration of the Feely and Sabine work to include the broader constraints of benthic processes (dissolution and sulfate reduction on margins), dissolution in the water column determined from trap data, export estimates derived from alkalinity models run with the GCM, export and standing stock data derived from satellite imagry and more! We are just at the incipient stage of integrated, SMP work, but look forward to being a part of the larger group.
DATA:	no data submitted
PUBLICATIONS:	no publications listed
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INVESTIGATOR INFORMATION:	Will Berelson Department of Earth Sciences University of Southern California Los Angeles, CA 90089-0740 tel: (213) 740-5828 fax: (213) 740-8801 berelson@usc.edu http://www.usc.edu/dept/earth/people/berelson/index.html William M. Balch Bigelow Laboratory for Ocean Sciences PO Box 475 West Boothbay Harbor, Maine 04575 tel: (207) 586-5255 fax: (207) 633-9641 bbalch@bigelow.org http://www.bigelow.org/pi/Balch.html Richard A. Feely NOAA/PMEL 7600 Sand Point Way NE Seattle, WA 98115 tel: (206) 526-6214 fax: (206) 526-6744 feely@pmel.noaa.gov Raymond G. Najjar Department of Meteorology Pennsylvania State University 522 Walker Building University Park, PA 16802-5013 tel: (814) 863-1586 fax: (814) 863-3663 najjar@essc.psu.edu http://www.essc.psu.edu/~najjar/ Christopher L. Sabine NOAA/PMEL 7600 Sandpoint Way NE Seattle, WA 98115 tel: (206) 526-4809 fax: (206) 526-6744 sabine@pmel.noaa.gov http://www.pmel.noaa.gov/~sabine/index.html Kitack Lee School of Environmental Science and Engineering Pohang University of Science and Technology San 31, Hyoja-dong, Nam-gu Pohang, 790-784 Republic of Korea (formerly NOAA/AOML/OCD) tel: 82-054-279-2285 fax: 82-279-8299 ktl@postech.ac.kr