A Science Plan for Carbon Cycle Research in North American Coastal Waters
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A Science Plan For Carbon Cycle Research In North American Coastal Waters Table of Contents Executive Summary .................................................................................................................. 5 Introduction ................................................................................................................................ 6 Overarching Science Questions .............................................................................................. 8 North American Coastal Regions ........................................................................................... 8 Gulf of Mexico ..................................................................................................................................... 8 Regional Setting ............................................................................................................................................... 8 Synthesis Findings and Remaining Gaps .............................................................................................. 9 Atlantic Coast .................................................................................................................................... 11 Regional Setting ............................................................................................................................................. 11 Synthesis Findings and Remaining Gaps ............................................................................................ 11 Pacific Coast ...................................................................................................................................... 15 Regional Setting ............................................................................................................................................. 15 Synthesis Findings and Remaining Gaps ............................................................................................ 18 Arctic ................................................................................................................................................... 20 Regional Setting ............................................................................................................................................. 20 Synthesis Findings and Remaining Gaps ............................................................................................ 22 Laurentian Great Lakes .................................................................................................................. 23 Regional Setting ............................................................................................................................................. 23 Synthesis Findings and Remaining Gaps ............................................................................................ 24 Fluxes and Processes .............................................................................................................. 26 Terrestrial Inputs ............................................................................................................................. 26 Rivers ................................................................................................................................................................. 26 Groundwater ................................................................................................................................................... 28 Biological Transformations ............................................................................................................ 29 Primary Production ..................................................................................................................................... 30 Respiration ...................................................................................................................................................... 33 Net ECosystem ProduCtion ........................................................................................................................ 33 VertiCal Fluxes, Export Production, and New Production ........................................................... 34 Other Transformations ............................................................................................................................... 35 Sedimentary Processes .................................................................................................................... 35 PartiCle Export and Deposition ............................................................................................................... 36 Temporary Storage and BiogeoChemiCal Transformations ....................................................... 36 Long-term Sequestration and Burial .................................................................................................... 37 Overall Fate of Carbon and Carbon-relevant Constituents in Sediments ............................. 38 Atmospheric Exchanges .................................................................................................................. 39 ExChanges with Estuaries .......................................................................................................................... 39 ExChanges with Tidal Wetlands .............................................................................................................. 40 ExChanges with Shelf Waters ................................................................................................................... 41 Coastal Methane Fluxes .............................................................................................................................. 42 Lateral Transport ............................................................................................................................. 44 Overarching Priorities and Recommendations ................................................................ 46 Acknowledgments ................................................................................................................... 47 2 References ................................................................................................................................ 49 Appendix 1. CCARS Workshop Materials ....................................................................... 65 Appendix 2. Participants of Previous CCARS Activities ............................................... 74 3 A Science Plan For Carbon Cycle Research In North American Coastal Waters Authors Heather Benway, Simone Alin, Elizabeth Boyer, Wei-Jun Cai, Paula Coble, Jessica Cross, Marjorie Friedrichs, Miguel Goñi, Peter Griffith, Maria Herrmann, Steven Lohrenz, Jeremy Mathis, Galen McKinley, Raymond Najjar, Cynthia Pilskaln, Samantha Siedlecki, Richard Smith The North American coastal interim synthesis activity, which is endorsed by the US Carbon Cycle Science Program, is coordinated by the Ocean Carbon & Biogeochemistry (OCB) Program (www.us-ocb.org) and the North American Carbon Program (NACP) (http://nacarbon.org/nacp/). Funding for the Coastal CARbon Synthesis (CCARS) activities was provided by NSF (1107285) and NASA (NNX10AU78G). The statements, findings, conclusions, and recommendations are those of the authors and do not necessarily reflect the views of any agency or program. Recommended citation: Benway, H., Alin, S., Boyer, E., Cai, W.-J., Coble, P., Cross, J., Friedrichs, M., Goñi, M., Griffith, P., Herrmann, M., Lohrenz, S., Mathis, J., McKinley, G., Najjar, R., Pilskaln, C., Siedlecki, S., Smith, R., 2016. A Science Plan for Carbon Cycle Research in North American Coastal Waters. Report of the Coastal CARbon Synthesis (CCARS) community workshop, August 19-21, 2014, Ocean Carbon and Biogeochemistry Program and North American Carbon Program, 84 pp. 4 Executive Summary Relative to their surface area, continental margins represent some of the largest carbon fluxes in the global ocean, but sparse and sporadic sampling in space and time makes these systems difficult to characterize and quantify. Recognizing the importance of continental margins to the overall North American carbon budget, terrestrial and marine carbon cycle scientists have been collaborating on a series of synthesis, carbon budgeting, and modeling exercises for coastal regions of North America, which include the Gulf of Mexico, the Laurentian Great Lakes (LGL), and the coastal waters of the Atlantic, Pacific, and Arctic Oceans. The Coastal CARbon Synthesis (CCARS) workshops and research activities have been conducted over the past several years as a partner activity between the Ocean Carbon and Biogeochemistry (OCB) Program and the North American Carbon Program (NACP) to synthesize existing data and improve quantitative assessments of the North American carbon budget. CCARS activities in all five regions resulted in data compilations that improved estimates of key carbon fluxes, particularly air-sea fluxes and primary productivity, for which the most observations exist. Updated carbon budgets have been published for the Gulf of Mexico (Coble et al., 2010; Benway and Coble, 2014), Atlantic coast (Najjar et al., 2012), Pacific coast (Alin et al., 2012), Arctic coast (Cross et al., 2014a, b; Evans et al., 2015), and the LGL (McKinley et al., 2011). Air-sea CO2 flux syntheses have been published for coastal systems of the Arctic (Cross et al., 2014a; Evans et al., 2015), Atlantic (Signorini et al., 2013), and the northern Gulf of Mexico (Huang et al., 2015), and more are underway. For the California