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Abstract

Arctic sea-ice decline has tremendous impacts on air-sea gas and heat exchange. The disappearance of sea ice due to ongoing global warming exposes more open-water areas to the atmosphere, thereby promoting the physical air–sea gas exchange as well as changing the heat content of the ocean. We examine regional and temporal changes in surface ocean pCO2 in the Arctic using neural-network based pCO2 estimates and relate them to sea-ice changes from satellite data. From first analyses, we find an increase in the intra-annual variability of pCO2 since 1980 in nearly all regions and – depending on the product and region – an acceleration of the tendencies over time. Separating the thermally-driven component from the component that is governed by non-thermal drivers, we infer how much of the observed changes in pCO2 can be attributed to a warming of the surface ocean layer and how much is influenced by other drivers. Finally, we link those findings to the regional and seasonal evolution of sea-ice coverage. With our findings, we aim for a better understanding of the oceanic carbon cycle in the Arctic seas which should lead to better predictability of future changes in surface pCO2 in high-latitude regions.