Influence of Cirrus Clouds on the Estimate of Sea Surface Temperature

Abstract

Because of the thin optical depth, the cirrus cloud is one the clouds that commonly overlooked as clear sky by the cloud mask products. To study the influence of cirrus clouds on the satellite thermal infrared (TIR) data estimated sea surface temperature (SST), the MODIS Terra SST products are used in this study. Six buoy stations measured sea temperatures are acquired from National Oceanic and Atmospheric Administration’s National Data Buoy Center (NDBC). In addition, the cirrus optical depth are calculated based on the cirrus reflectance of MODIS cloud mask products. The SST pixels with MODIS cloud products labeled as confident clear-sky and cirrus reflectance flag is cirrus or contrail pixel are taken as cirrus pixels. Taking buoy sea temperatures as the true values, the MODIS SST errors are between 1.2 K and -0.6 K. In addition, five stations’ MODIS SST are tend to underestimated as cirrus optical depth increase.