The multi-and quasi-decadal variabilities of the sea surface temperature (SST) anomaly over the North Atlantic are investigated by means of two-dintensional propagating CEOR Forty-six years of the COADS SST dataset from 1947 to 1992 are used. After removing the monthly climatology and four-year low-pass filtering the SST anomaly is submitted to CEOR The total variance of the three largest modes accounts for 87.0% of the total variance. Mode 1 is a very slow oscillation with an approximate 42-yr period and has basinwide spatial evolution, with alternate warm and cold anomalies appearing off Newfoundland and migrating northward until they disappear south of Greenland. The center of action of the anomalies both occur in the vicinity of the Labrador Sea. Newfoundland, and south of Greenland where deep-water formation takes place. Mode 2 + 3 is a quasi-decadal ftuctuation with an approximate 14-yr period. Mode 2 + 3 contains quasidecadal timescales with alternating warm and cold anomalies propagating from the Labrador Sea eastward following the North Atlantic Current and the subpolar gyre.

[1] The decadal variability of the convective activity in the Labrador Sea is investigated using 43 years of model output from a prognostic coupled ice-ocean model that simulates both the Arctic and the North Atlantic Oceans. The fields of the surface density and the mixed-layer depth indicate that the center of the convective activity is located in western Labrador Sea. The decadal variations of the convective depth are controlled to large extent by the oceanic preconditioning associated with changes in subsurface stratification. The intensity of the convective mixing varies from year to year, depending upon how strong the isopycnal doming is at the preconditioning stage at the center of the convective region. The variations of the subsurface stratification seem to be related to the subsurface temperature changes.