The optimum interpolation sea surface temperature (OI SST V2) analysis produced weekly by NOAA on a one-degree surface grid were discontinued in October 2022. The calculated SST anomalies were based on 1982-2000 climatology.
The new data source from NOAA consists of daily sea surface temperature at 0.25 degree grid. (OI SST V2.1). The anomalies are based on 1971-2000 climatology.
NOAA OI SST V2 High Resolution Dataset data provided by the NOAA PSL, Boulder, Colorado, USA, from https://www.ncei.noaa.gov/products/optimum-interpolation-sst
Huang, B., Liu, C., Banzon, V., Freeman, E., Graham, G., Hankins, B., Smith, T., and Zhang, H. (2021). Improvements of the Daily Optimum Interpolation Sea Surface Temperature (DOISST) Version 2.1. Journal of Climate 34, 8, 2923-2939, available from https://doi.org/10.1175/JCLI-D-20-0166.1