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Oceanography
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Comparative Performance of SST Algorithms In the Tropical Ocean Using OCTS Data
9.0 Generation of SST Maps
Both algorithms were applied to the thermal infrared bands to generate SST maps. The land and cloud areas were masked out. Figure 3 shows the generated SST maps for the image date of 21 April 1997 using the two algorithms. Similar SST patterns are shown by both images.
10.0 Conclusion
The results of the study indicated that the performance of the developed algorithm is comparable to the established NASDA MCSST algorithm. However, this algorithm requires only two thermal infrared bands instead of three bands used by NASDA. This algorithm takes into account of the local atmospheric condition. The retrieved SST values are highly correlated with the NASDA MCSST computed values. The computed values using the proposed algorithm deviated by a small amount from the MCSST retrieval values. The typical SST values in the studied region were between 28°C to 31°C. However very little points having these values were used in NASDA calibration analysis and some of these points showed higher in-situ values than the computed values. At higher temperatures, proposed algorithm gave slightly higher values than those computed using NASDA MCSST. Based on the analysis, proposed algorithm is capable to produce reliable results. The present study has indicated that it is possible to use this algorithm globally. It requires the knowledge of the atmospheric transmittance at the study location. Coincident SST values are needed for more accurate verification. This will be verified by pursuing further research.
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Figure 3 SST maps on 21 April 1997 using (a) the proposed algorithm and (b) NASDA algorithm (colour code: blue 28-29°C, green 29-30°C, yellow 30-31°C, orange > 31°C, white for cloud and brown for land areas)
Acknowledgments
This study is partially supported by NASDA through the joint NASDA-ESCAP project. Thanks are extended to RESTEC, the Universiti Sains Malaysia and the Malaysian Meteorological Service.
References
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