A Prognostic Scheme of Sea Srrface Skin Temperature for Modeling and Data Assimilation

In atmospheric data assimilation, weather forecasting, and atmospheric modeling, the term sea surface temperature (SST) usually refers to the (five-day to monthly) product of blended satellite retrievals and in situ measurements at a depth of a few centimeters to a few meters from buoys and ships. In oceanic and ocean-atmosphere coupled modeling, the term SST refers to the mean temperature of the top ocean layer of about 10 meters in depth. Numerous studies have demonstrated that these temperatures are significantly different from the sea surface skin temperature, but these approaches are less suitable for modeling and operational data assimilation.

We have developed a physically-based prognostic scheme for the computation of sea surface skin temperature in weather forecasting, four-dimensional data assimilation, and ocean-atmosphere coupled modeling. This scheme is then tested using the in situ data over tropical and midlatitude oceans. By implementing this scheme into the ECMWF model, the diurnal variation of sea surface temperature as measured by the geostationary satellite can also be reproduced.