Changing Biogeochemistry of the Arctic Ocean: Surface Nutrient and CO2 Cycling in a Warming, Melting North

Abstract

The physical system of the Arctic is changing in profound ways, with implications for the transport of nutrients to and from the Arctic Ocean as well as the internal cycling of material on shelves and in deep basins. Significant increases in Arctic Ocean primary production have been observed in the last two decades, potentially driven by enhancements to a suite of mechanisms that increase nutrient availability to upper ocean waters, including transport from adjacent subpolar regions, storm-induced mixing, and mobilization of nutrients from terrestrial pools. The relative strength of these mechanisms varies substantially within Arctic Ocean subregions, leading to a mosaic of biogeochemical responses. Changes in primary production are also driving regional changes in the biologically mediated air-sea exchange of CO2, while warming, enhanced stratification, and increased mobilization of carbon from terrestrial pools are also driving regionally variable trends.