Interlinks between sea-ice melting and continental wetting under a changing Arctic moisture transport and dipole-like circulation

Abrupt Arctic warming has profound implications for both polar and mid-latitude climates, with moisture transport playing a central role in Arctic amplification. Using a tagged water vapor transport model driven by three reanalysis datasets, we quantify seasonal Arctic moisture transport during 1980–2024 and evaluate the inter-dataset spread. Robust features across all datasets indicate that summer moistening is primarily caused by increased inflow of continental moisture, while autumnal moistening is dominated by local evaporation over the Arctic Ocean. This moisture transport is largely governed by Arctic Dipole pattern (ADP). Increased Arctic moisture induces sea-ice melting through the enhancement of downward longwave radiation.

Simulations provide evidence that sea-ice retreat can promote ADP-like circulation through enhanced Arctic thermal forcing. A linear baroclinic model diagnosis shows that the observed sea level pressure trend projects most strongly onto an ADP-like mode forced by near-surface heating along the Eurasian Arctic coast, where recent sea-ice retreat is pronounced. Complementary AGCM experiments using six future Arctic warming boundary conditions consistently reproduce ADP-like circulation anomalies, characterized by lower pressure over the Arctic Ocean and higher pressure near Greenland. These responses are accompanied by substantial sea-ice loss and enhanced upward turbulent heat fluxes along the ice margins, especially over the Barents–Kara Seas. Across the experiments, sea-ice extent is strongly linked to Siberian coastal pressure anomalies, supporting a dynamical connection between sea-ice loss and ADP development. Although sea-ice forcing alone may not fully explain the observed tropospheric response, the results suggest a broader coupled feedback among sea ice, moisture transport, and large-scale circulation.

Our findings highlight both the robust and uncertain components of the Arctic moisture cycle and emphasize the need to better constrain surface evaporation in Arctic climate modeling.