1040 / 2024-09-20 09:32:42

Aged Dissolved Organic Carbon in the Little America Basin, Ross Sea: Insights from Radiocarbon

Dissolved Organic Carbon,Ross Sea,Radiocarbon

Ross Sea continental shelf is one of the most productive region in the Southern Ocean, playing a key role in deep water formation and carbon cycling. In this study, we examined radiocarbon (¹⁴C) content in dissolved organic carbon (DOC) to investigate the sources and circulation of DOC in the Little America Basin, Ross Sea. The ¹⁴C age of DOC throughout the water column was as old as, or older than, the deep Pacific DOC. Surface DOC was older than that in the deeper water unlike the typical oceanic distribution. On the keeling plot (1/[DOC] vs △¹⁴C) our data aligned along a separate line with a positive slope, deviating from the global trend, which typically shows a negative slope. The results suggest that very old DOC is being introduced into the surface layer. The potential sources and overall circulation of DOC in the Little America Basin will be discussed.