ECMWF's current ocean reanalysis uses a sophisticated data assimilation methodology which includes a model bias correction. The ocean model used is forced by atmospheric daily surface fluxes, relaxed to SST and bias corrected.
The Balmaseda et al (QJRMS 2013) reference provides excellent peer reviewed documentation and evaluation.
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|Ocean basin meridional overturning circulation (source ECMWF).|
|ORSA4 SST anomaly Sept, 2012 (source ECMWF).|
|ORSA4 potential temperature anomaly longitude vs depth cross section Sept, 2012 (source ECMWF).|
|ORSA4 equatorial SST anomalies (source ECMWF).|
|ORSA4 western Pacific SST anomalies (source ECMWF).|
National Center for Atmospheric Research Staff (Eds). Last modified 13 Oct 2016. "The Climate Data Guide: ORAS4: ECMWF Ocean Reanalysis and derived ocean heat content." Retrieved from https://climatedataguide.ucar.edu/climate-data/oras4-ecmwf-ocean-reanalysis-and-derived-ocean-heat-content.