Statistical analysis of sea surface temperature in the North Atlantic Ocean

The oceans have significant heat storage capacity and provide a considerable source of thermal inertia to the overlying atmosphere. The oceanic thermal inertia is transmitted to the atmosphere mainly via the surface turbulent fluxes of sensible and latent energy. These fluxes depend upon the sea surface temperature (SST), and several atmospheric parameters. Given the importance of SST in the thermal communication between the ocean and atmosphere, and the potential for SST variations to induce slow climatic fluctuations, it is of interest to investigate the nature of temporal persistence of large-scale SST anomalies. In the present study, we focused on understanding the behavior of SST anomaly persistence in the North Atlantic using statistical tools. We investigated possible covariance in the monthly SST residuals for the North Atlantic Ocean, derived from long-term observations from the time interval 1856 - 2008. Data used are based on the monthly SST for North Atlantic Ocean, area averaged between latitudes 0 and 70 N. The multiyear SST time series for all twelve months were treated and compared. A linear fit trend and a multidecadal oscillation are removed from the data to obtain approximate stationary conditions for the time series. The resulted SST monthly residuals form a matrix which shows significant covariance, indicative of SST anomalies persistence at time scale of several months. Implications for the ocean – atmosphere interactions and possible climate effects in the North Atlantic region are discussed.