NOAA 1/4-degree Daily Optimum Interpolation Sea Surface Temperature (OISST) Analysis from AVHRR and AMSR, Version 2

This high-resolution sea surface temperature (SST) analysis product was developed using an optimum interpolation (OI) technique. The SST analysis has a spatial grid resolution of 0.25 (1/4) degree and temporal resolution of 1 day. The product uses Advanced Very High Resolution Radiometer (AVHRR) infrared satellite data from the Pathfinder AVHRR SST dataset and additional microwave satellite data from the Advanced Microwave Scanning Radiometer on the EOS platform (AMSR-E), which was available from 2002 to 2011. AMSR-E data has a spatial resolution of ~25 km, while AVHRR data has a spatial resolution of ~4 km. AMSR-E can observe SST through cloud cover, resulting in significantly better spatial coverage. AVHRR data is needed in part because AMSR-E does not provide reliable SSTs along coastal regions due to its coarser spatial resolution. Thus, with AVHRR+AMSR, the observations near land come from AVHRR, while AMSR-E has superior spatial coverage over the open ocean. Because of AMSR-E’s almost all-weather capability, the AVHRR+AMSR version provides more accurate information in persistently cloudy areas and during hurricanes and storms. However, even in cloud-free regions, the combined use of infrared and microwave data reduces systematic biases due to the independent error characteristics of the two sensors. The AVHRR+AMSR SST production ended in Oct 2011 when the AMSR-E antenna failed.