Simone R. Alin, NOAA/PMEL

The North American Carbon Program (NACP) Coastal Interim Synthesis Activity: Carbon synthesis along North American margins

Simone R. Alin, NOAA/PMEL David Archer, University of Chicago Heather Benway, OCB/WHOI Wei-Jun Cai, University of Georgia Feizhou Chen, Dalhousie University Paula Coble, University of South Florida Richard A. Feely, NOAA/PMEL Katja Fennel, Dalhousie University Marjy Friedrichs, Virginia Institute of Marine Science Peter Griffiths, NASA Goddard Space Flight Center Nicolas Gruber, Eldgenössische Technische Hochschule (ETH) Zürich Burke Hales, Oregon State University Martin Hernandez, Universidad Autonoma de Baja California Bror Jönsson, Boston University Beverly E. Law, Oregon State University Mingliang Liu, Auburn University Steven E. Lohrenz, University of Southern Mississippi Amala Mahadevan, Boston University Jeremy T. Mathis, University of Alaska Fairbanks Wade McGillis, Columbia University Galen McKinley, University of Wisconsin Ray Najjar, Pennsylvania State University Gian-Kasper Plattner, Eldgenössische Technische Hochschule (ETH) Zürich Peter Raymond, Yale University Christopher L. Sabine, NOAA/PMEL Joe Salisbury, University of New Hampshire Elizabeth H. Shadwick, Dalhousie University Samantha Siedlecki, University of Chicago Peter Strutton, Oregon State University Helmuth Thomas, Dalhousie University Hanqin Tian, Auburn University Doug Vandemark, University of New Hampshire Andrea Vander Woude, Oregon State University

Coastal oceans have important and complex linkages with terrestrial, atmospheric, and open ocean biogeochemical cycles. The goal of the NACP Coastal Interim Synthesis Activity is to stimulate synthesis of small-scale studies across broader spatial and temporal scales to improve estimates of the magnitude, spatial distribution, and inter-annual variability of carbon sources and sinks in coastal waters. We encourage broad participation of researchers focused on organic (OC) and inorganic carbon, as well as related aspects of nitrogen (N), phosphorus (P), and oxygen (O) cycling. Participating investigators will facilitate data mining and recovery by creating metadata on the NACP website to identify existing data products and centers.

The coastal synthesis activity is divided into five regions: Atlantic (including Gulf of Maine & Scotian Shelf)—Carbon cycling on the Atlantic coast has been studied for >30 years. Recent field and satellite-based studies have yielded new insights into the relative dominance of dissolved vs. particulate OC in coastal C budgets, the importance of river inputs on air-sea exchange and ocean acidification, and inter-annual variability. Biogeochemical models for the east coast are being used to assess sources, sinks, transformations, and fate of C on the shelf; interactions between N, C, and O cycling; and influences of future climate change.

Pacific—Recent observations have dramatically improved data coverage of surface ocean CO2 along the west coast, as well as terrestrial atmospheric CO2, soil carbon stocks, and terrestrial C fluxes. Satellite-based synthesis methods and new observations have yielded revised estimates of the strength of the west coast CO2 sink and have also improved sampling coverage and process understanding in previously undersampled areas. Efforts toward a west coast model-data synthesis comparison are beginning.

Gulf of Mexico— The Gulf of Mexico (GOM) has substantial influence on the continental carbon budget because prevailing winds carry GOM air masses over NA and outward over the east coast. Recent observations and modeling efforts have provided additional information about sources and sinks of CO2 in the GOM, the importance of river inputs of carbon and nutrients through time, and seasonal and regional gradients in air-sea fluxes. Synthesis and model development efforts for the GOM are underway.

Arctic and marginal seas—Recent observations in the Arctic, Bering, and Beaufort basins have provided new insights into our understanding of the high-latitude marine carbon cycle (MCC), particularly at the land-ocean and ocean-atmosphere interfaces. These regions act as strong seasonal sinks for atmospheric CO2 and thus have a greater sensitivity to anthropogenically- induced changes in the MCC. Intensive, year-round observations will yield insight into seasonal CO2 system variability and the importance of biological activity, terrestrial inputs, and exchange between the Pacific and Atlantic. Carbon budgets are being developed.

Great Lakes—While it is generally accepted that small lakes are sources of CO2 to the atmosphere due to their processing of terrestrial carbon, the role of the Great Lakes is less clear. Observations in coastal Lake Superior indicate significant supersaturation over much of the year, but recent modeling work suggests that the lake is in approximate balance with the atmosphere over the annual cycle. A community carbon budgeting effort for the Great Lakes is just beginning.

(2987 of 3000 characters allowed)