RADIOMETRIC VALIDATION OF ERS-1 ALONG-TRACK SCANNING RADIOMETER AVERAGE SEA-SURFACE TEMPERATURE IN THE ATLANTIC-OCEAN

The ERS-1 along-track scanning radiometer (ATSR) provides a half-degre e latitude by half-degree longitude average sea surface temperature (A SST) measurement representative of:he thermal skin layer of the ocean that is intended for use in global climate studies. Radiometric skin s ea surface temperature (SSST) and bulk sea surface temperature (BSST) observations are presented that have been collected spatially coincide nt and near contemporaneously with ERS-1 ATSR ASST in the tropical and subtropical Atlantic Ocean during September 1992. Using these data th e authors demonstrate that the ERS-1 ATSR ASST (SADIST 600) computed f rom both forward and nadir observations (dual ASST) has a cool bias of -0.54 K, and the ASST computed from nadir-only observations has a bia s of -0.78 K. The rms scatter about the mean bias for the dual ASST is 0.18 K and for the nadir ASST is 0.22 K, demonstrating the effectiven ess of the along-track scanning concept. The difference between SSST a nd BSST validation techniques is less than 0.05 K because high wind sp eeds dominate the in situ dataset, preventing an appreciable skin temp erature deviation at the air-sea interface. Most of the bias described above can be explained by Saharan dust and aerosols from the Mount Hu dson and Mount Pinatubo volcanic eruptions that were present in the at mosphere during the measurement period.