Spatial variation and species transformation of 129I and 127I in the Central Arctic Ocean

The spatial distributions of anthropogenic 129I and natural 127I in iodide (I−) iodate (IO3−) were investigated the upper central Arctic Ocean. results show that molecular ratios reductive to oxidative ranged from 0.228 0.560 for 0.383 0.827 Polar Mixed Layer (PML). Greater 127I− concentrations markedly higher I−/IO3− both found PML over Lomonosov Alpha Ridges. This suggests in-situ formation I− occurs as a result enhanced environments at these locations due bacterial-mediated decomposition dissolved organic matter (DOM) likely originates inflow river water into Ratios 129I−/129IO3− 127I−/127IO3− decrease gradually along main transport pathway Atlantic water, revealing is oxidized back IO3− slow net rate within Water Layer. Our study provides insights marine geochemical cycling iodine raises potential species, notably 129I, be used indicators changes redox condition surface Ocean, which may occur predicted impacts climate change.