Monday, April 20, 2020

The PO.DAAC is pleased to announce the public release of the NOAA NCEI GHRSST Level-4 Optimally Interpolated (OI) Sea Surface Temperature (SST) v2.1 dataset. This dataset is produced by NOAA’s National Centers for Environmental Information (NCEI) and derived from their Optimal Interpolation (OI) algorithm by interpolating and extrapolating SST observations from multiple sources, including the Advanced Very High Resolution Radiometer (AVHRR) satellites and in-situ measurements. It is formatted in netCDF, in full compliance with the Group for High-Resolution Sea Surface Temperature (GHRSST) Data Specification (GDS2). Each file provides daily global foundation SST solution at 0.25-degree spatial resolution with a latency of 24 hours.  

The v2.1 is the updated version from the current v2.0 (AVHRR_OI-NCEI-L4-GLOB-v2.0). The new version has incorporated several enhancements, including 1) In-situ ship and buoy data changed from the NCEP Traditional Alphanumeric Codes (TAC) to the NCEI merged TAC + Binary Universal Form for the Representation (BUFR) data, with large increases in buoy data sample size used to correct satellite SST biases; 2) Addition of Argo float observed SST data, for further correction of satellite SST biases; 3) Satellite input from the MetOp-A and NOAA-19 AVHRRs removing poor satellite data; 4) Revised ship-buoy SST corrections for  improved accuracy; and 5) Revised sea-ice-concentration to SST conversion to remove warm biases in the Arctic region (Banzon et al. 2020). The v2.1 updates only apply to granules after Jan. 1st, 2016. The data pre 2016 are still the same as v2.0 except for metadata upgrades.

The dataset is described and discoverable via the PO.DAAC dataset information page. The dataset information page also provides access to the technical documentation, including the SST algorithm ATBD, data reprocessing overview, and guidance on how to cite the data. 



Reynolds, R. W., T. M. Smith, C. Liu, D. B. Chelton, K. S. Casey and M. G. Schlax, 2007: Daily High-resolution Blended Analyses for sea surface temperature. J. Climate, 20, 5473-5496

Banzon V. 2020, Improved Estimation of Proxy Sea Surface Temperature in the Arctic, American Meteorological Society,

Comments/Questions? Please contact or visit the PO.DAAC Forum.