Sea surface height variability shapes Siberian Arctic Ocean circulation and Pacific Water inflow

The Siberian Arctic Ocean links river runoff, sea ice, and Pacific–Atlantic exchanges, yet the drivers of its circulation variability remain poorly constrained. Using multi-decadal satellite altimetry, ocean reanalysis products, and in situ observations with cyclostationary empirical orthogonal function analysis, we show that shelf and slope currents are governed by distinct mechanisms across timescales. Seasonally, the Eastern Siberian Shelf Current is primarily regulated by salinity-driven sea-surface-height (SSH) gradients, with winds secondary, whereas the narrow Siberian Coastal Current is buoyancy-driven and strongly enhanced by summer winds. Interannually, the Siberian Slope Current captures a recent atmospheric transition from the Arctic Oscillation to the Arctic Dipole. We further identify a Siberia–Alaska sea-level-pressure dipole that modulates SSH gradients and regulates Pacific Water inflow through the Bering Strait, providing a physically based inflow index. Overall, SSH integrates buoyancy forcing, wind-driven circulation, and basin-scale atmospheric variability, identifying the Siberian Arctic Ocean as a key region for Arctic Ocean circulation and climate variability.