Synthesis & Modeling Project

Will Berelson
William M. Balch
Richard A. Feely
Raymond Najjar
Christopher L. Sabine

Kitack Lee

Production and Dissolution of Calcium Carbonate in the Global Ocean: A synthesis and modeling project


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:
  1. 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.
  2. 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.
  3. 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.
  4. 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.


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Will Berelson
Department of Earth Sciences
University of Southern California
Los Angeles, CA 90089-0740
tel: (213) 740-5828
fax: (213) 740-8801

William M. Balch
Bigelow Laboratory for Ocean Sciences
PO Box 475
West Boothbay Harbor, Maine 04575
tel: (207) 586-5255
fax: (207) 633-9641

Richard A. Feely
7600 Sand Point Way NE 
Seattle, WA 98115 
tel: (206) 526-6214 
fax: (206) 526-6744 

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

Christopher L. Sabine
7600 Sandpoint Way NE
Seattle, WA 98115
tel: (206) 526-4809
fax: (206) 526-6744

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