Spatiotemporal patterns of decadal variability in sea surface temperature, wind speed, and sea level pressure in the North Atlantic

Abstract

Spatiotemporal patterns of decadal variability in sea surface temperature, atmospheric pressure, and surface wind speed are obtained from the COADS data set by the cluster analysis technique. Sequences of typical structures and their coupling over the last 42 years are examined. On decadal time scales, the pressure and wind anomaly fields are found to roughly satisfy the geostrophic balance. A mode associated with the well-known North Atlantic Oscillation is identified in these fields. Other modes of decadal variability-the tropical dipole, the subtropical-gyre mode, and the thermohaline mode in the high-latitude North Atlantic-are found in SST anomalies. The global dipole SST mode for the entire Atlantic Ocean is interpreted from the standpoint of the variability in the intensity of the Atlantic branch of the global interoceanic thermohaline circulation (the conveyer belt). A difference in this coupling for the Atlantic and Pacific oceans is noted.