The relationship between the 0°C isotherm and atmospheric forcing in the Arctic Ocean

Abstract

Empirical Orthogonal Function (EOF) analysis was performed on the gridded data of the depth to the 0°C isotherm to better understand Atlantic layer variability in the Arctic Ocean. The first mode accounts for 51% of the total variance. The second mode accounts for 26% of the variance, and shows high variability in the region of inflow from the Barents Sea, and large but oppositely signed variability in the region near the Canadian Archipelago and along the path of the Transpolar Drift. This second mode is correlated with the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) indices. Composite analyses of the data using the AO and NAO indices to partition the data reinforces the physical relationship between the second EOF and atmospheric forcing. This study shows that the variability of the Atlantic Layer characterized by the 0°C isotherm across the Arctic Ocean is significantly correlated with atmospheric driving.