Interactions within the Ocean-Ice-Atmosphere Systems of the North Pacific and the North Atlantic

摘要

Four regional indices of sea ice variability and thirty years of monthly sea surface temperature (SST) and sea level pressure (SLP) data are used to evaluate the large-scale interactions within the ocean-ice-atmosphere systems of the North Pacific and the North Atlantic. A direct association between positive (negative) SST anomalies and light (heavy) ice in the Bering Sea is indicated. The SST/ice coupling in the northern Alaskan waters is also statistically significant. The SST anomalies in both the North Pacific and the North Atlantic appear as persistent responses to atmospheric forcing. The SLP distributions over both oceans correlate significantly with the arctic SLP distribution, although the midlatitude atmospheric circulation shows no systematic tendency to lead to lag the arctic circulation. Sea ice fluctuations correlate most highly with the atmospheric forcing over antecedent periods of approximately 9 months in the northern Alaskan waters, 3-4 months in the Bering Sea, and 5-7 months in the East Greenland Sea. The strength of the 9-month mean onshore air flow component describes over 70% of the northern Alaskan ice variance. (Author)