Arctic sea ice has exhibited a sustained long-term declining trend in response to accelerating global warming. Notably, a pronounced regime shift characterized by abrupt changes in sea ice extent and thickness was reported around 2007. Such sea ice decline can induce a variety of feedback through atmosphere–ocean interactions, highlighting the need for an understanding of its impacts and mechanisms across the Arctic marine environment. The Chukchi Slope Current (CSC), flowing along the continental slope of the Chukchi Sea in the western Arctic, is one of the key circulation mechanisms transporting Pacific Water into the interior Arctic basin. Recently, increasing temperatures of Pacific Water have further emphasized the importance of the CSC. This study investigates changes in the CSC before and after the 2007 regime shift using in-situ data and the GLORYS12v1 ocean reanalysis model. The long-term trend of the CSC transport increased by approximately 0.2 Sv after the regime shift, which is attributed to an increase in steric height associated with freshwater accumulation in the Beaufort Sea. In addition, the seasonal variability of the CSC increased by about 98% after the regime shift, which is interpreted as a result of the extended open-water duration due to sea-ice decline and the consequent strengthening of air–sea interactions. This study suggests that Arctic sea-ice decline could enhance and accelerate the transport of warmer Pacific Water into the Arctic basin through the CSC.

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