Sea surface temperature estimation using active/passive microwave remote sensing

Although the sea surface temperature (SST) is often estimated from satellite infrared observations, passive microwave techniques have the advantage of being applicable in cloudy regions. However, sea surface temperature estimated by passive microwave techniques is subject to errors related to variations in wind speed and foam coverage. The goal of this research is to combine active and passive microwave measurements to improve the accuracy of SST retrievals. A non-linear iterative inversion method for the retrieval of both surface wind and sea surface temperature using spaceborne microwave scatterometer and radiometer measurements is developed and applied to data collected by the SeaSat satellite. The results show that SST can be reliably estimated from SeaSat SASS/SMMR measurements for an open ocean area. The averaged test-site correlation coefficient between the reference SST (measured by ships) and the SeaSat-based estimates of SST is 0.8916 and the corresponding standard errors are smaller than 0.7/spl deg/C. These results suggest that a physically based retrieval scheme can be useful in improving the accuracy of SST measurements made by combining active and passive microwave remote sensing.