Sea surface temperature retrievals optimized to the East Sea (Sea of Japan) using NOAA AVHRR data

The accuracy of sea surface temperatures derived by NOAA/NESDIS (National O ceanic and Atmospheric Administration/National Environmental Satellite, Dat a, and Information Service) equations was tested by comparison With tempera tures measured by thirty-four satellite-tracked ARGOS drifters deployed in the East Sea (Sea of Japan) from 1993 to 1997. Using an improved cloud-scre ening algorithm for the East Sea, we obtained 362 matchup points between th e NOAA satellite data (NOAA-11, NOAA-12, and NOAA-14) and the drifter buoy temperatures. The split window technique of linear MCSST, non-linear CPSST and NLSST showed relatively small rms (root mean square) errors in the rang e of 0.9 degrees C to 1.2 degrees C compared with the other window methods. However, a predominant trend was found that satellite-derived SSTs are und erestimated by as much as -2 degrees C in dry atmospheric conditions during winter, and overestimated in very humid conditions in summer by approximat ely 2 degrees C. The characteristic trend was removed using a regression me thod, and the mts errors of newly-derived equations for the split window MC SST and the non-linear SST optimized to the East Sea were improved to withi n 0.3 degrees C similar to 0.9 degrees C. The locally-optimized SSTs may be more important than the SSTs based on the global database, particularly in the inaccessible regions off North Korea and sea ice regions that are impo rtant for the critical research issue of cold water formation in, the East Sea.