The relationship between the depth to the 0°C isotherm of the Arctic Ocean and atmospheric forcing

Abstract

Empirical Orthogonal Function (EOF) analyses of the depth to the 0°C isotherm of the Arctic Ocean were performed to determine the variability of the depth to the 0°C isotherm in the Arctic Ocean. The data are from the 'Environmental Working Group - Joint US. Russian Atlas of the Arctic Ocean.' The first three modes explain 99% of the total variance with each mode explaining 51 %, 26%, and 23%, respectively. Mode 1 shows the pattern of the outflow through Fram Strait and the Lincoln Sea. Mode 2 shows the variability of the inflow from the Barents Sea and the variability of the outflow through the Canadian Archipelago as well as the variability of the Transpolar Drift. Mode 2 has a close relationship with atmospheric conditions (Arctic Oscillation or North Atlantic Oscillation index). Mode 3 is significantly correlated with the annual mean vorticity index, when the vorticity index leads by 1 year. Composite analyses of the data using the AO, NAO, and vorticity index confirm that the EOF analyses of this study are valid. This study shows that the variability of the 0°C isotherm of the Arctic Ocean is significantly correlated with atmospheric conditions.