Predicting North Atlantic Sea Surface Temperature Variability Based On The First-mode Linear Baroclinic Rossby Wave Model

Predictability of sea surface temperature (SST) variations over the North Atlantic Ocean is studied based on the first-mode baroclinic Rossby wave model. This simple linear wave model can explain about 10%-46% of the wintertime SST variability in several regions of the North Atlantic basin, including the tropics between 5°N and 20°N, the eastern subtropics between 27°N and 34°N, and the east of Newfoundland.The wind-forced baroclinic Rossby waves can affect SST through different mechanisms in the tropics and subtropical-midlatitude North Atlantic. In the tropics, thermocline anomalies generated by the westward propagating Rossby waves affect SST predominantly through mean upwelling, but through winter mixed layer entrainment in the subtropical-midlatitude North Atlantic.It is shown that the wintertime SST anomalies can be skillfully predicted up to three months ahead in the tropical Atlantic, eighteen months in the eastern subtropical Atlantic, and three years east of Newfoundland based on the first-mode baroclinic Rossby wave adjustment. Using wind stress data from NCEP-NCAR, a prediction of the future low-frequency SST variability has been made.