Coupled ocean‐atmosphere loss of marine refractory dissolved organic carbon

The oceans hold a massive quantity of organic carbon, nearly all of which is dissolved and more than 95% is refractory, cycling through the oceans several times before complete removal. The vast reservoir of refractory dissolved organic carbon (RDOC) is a critical component of the global carbon cycle that is relevant to our understanding of fundamental marine biogeochemical processes and the role of the oceans in climate change with respect to long‐term storage and sequestration of atmospheric carbon dioxide. Here we show that RDOC includes surface‐active organic matter that can be incorporated into primary marine aerosol produced by bursting bubbles at the sea surface. We propose that this process will deliver RDOC from the sea surface to the atmosphere wherein its photochemical oxidation corresponds to a potentially important and hitherto unknown removal mechanism for marine RDOC. Key Points Dissolved organic carbon in the deep ocean contains organic surfactants Primary marine aerosol can be enriched in refractory dissolved organic carbon Atmospheric removal pathway for marine refractory dissolved organic carbon