Oceanic Efflux of Ancient Marine Dissolved Organic Carbon in Primary Marine Aerosol

Steven R Beaupre1, David J Kieber2, William C Keene3, Michael S Long4, John R Maben3, Xi Lu5, Yuting Zhu6, Amanda A Frossard7, Joanna D. Kinsey8, Patrick Duplessis9, Rachel Ying-Wen Chang10 and John Bisgrove11, (1)Stony Brook University, School of Marine and Atmospheric Sciences, Stony Brook, United States, (2)SUNY College of Environmental Science and Forestry, Department of Chemistry, Syracuse, United States, (3)University of Virginia, Department of Environmental Sciences, Charlottesville, VA, United States, (4)Harvard University, School of Engineering and Applied Sciences, Cambridge, United States, (5)Stony Brook University, Department of Electrical and Computer Engineering, Stony Brook, NY, United States, (6)Wadsworth Center, NYS Department of Health, Albany, United States, (7)University of Georgia, Department of Chemistry, Athens, United States, (8)Quinnipiac University, Hamden, United States, (9)Dalhousie University, Physics & Atmospheric Science, Halifax, NS, Canada, (10)Dalhousie University, Physics & Atmospheric Science, Halifax, Canada, (11)State University of New York, College of Environmental Science and Forestry, Department of Chemistry, Syracuse, NY, United States
Abstract:
Breaking waves produce bubble plumes that burst at the sea surface, injecting primary marine aerosol (PMA) highly enriched with marine organic carbon (OC) into the atmosphere. It is widely assumed this OC is modern, produced by present-day biological activity, even though nearly all marine OC is thousands of years old, produced by biological activity long ago. We used natural abundance radiocarbon (14C) measurements to show that 19 – 40% of the OC associated with freshly produced PMA was refractory dissolved organic carbon (RDOC). Globally, this process removes 2 – 20 Tg RDOC from the oceans annually, comparable to other RDOC losses. This process represents a significant removal pathway for old organic carbon from the sea, with important implications for oceanic and atmospheric biogeochemistry, the global carbon cycle, and climate.