Dissolved Organic Radiocarbon in the Eastern Pacific and Southern Oceans

We report marine dissolved organic carbon (DOC) concentrations, and DOC Delta C-14 and delta C-13 values in seawater collected from the Southern Ocean and eastern Pacific GOSHIP cruise P18 in 2016/2017. The aging of C-14 in DOC in circumpolar deep water northward from 69 degrees S to 20 degrees N was similar to that measured in dissolved inorganic carbon in the same samples, indicating that the transport of deep waters northward is the primary control of C-14 in DIC and DOC. Low DOC increment C-14 and delta C-13 measurements between 1,200 and 3,400 m depth may be evidence of a source of DOC produced in nearby hydrothermal ridge systems (East Pacific Rise).

Automated summary

The study found that marine dissolved organic carbon concentrations in the Southern Ocean and eastern Pacific are primarily controlled by the transport of deep waters northward. Low DOC increment C-14 and delta C-13 measurements at specific depths may indicate a source of DOC from nearby hydrothermal ridge systems.