Evaluation of the global ocean forecast system in NMEFC with the IV-TT class4 metrics

Abstract

Based on the IV-TT Class4 metrics, this paper comprehensively evaluates the forecasting performance of the National Marine Environment Forecast Center High-resolution Global Ocean Forecasting System (hereinafter referred to as NMEFC-NEMO) on sea surface temperature (SST), sea level anomaly (SLA) and temperature-salinity profiles. The RMSE of NMEFC-NEMO for SST and SLA over forecast length has the smallest error among the international operational systems, which are 0.45°C and 0.07m, respectively. The forecast accuracy of NMEFC-NEMO temperature and salt profile RMSE is in the middle among the operational systems, with the values of 0.69°C and 0.24 PSU. In the profile forecast, the error of NMEFC-NEMO is slightly larger than other systems at 50-100 m depth, which is related to the fact that NMEFC-NEMO does not assimilate ARGO temperature and salinity directly. In addition, with respect to the forecast skill scores, NMEFC-NEMO has a positive climatology skill scores for both SST and SLA, and the persistence skill scores for SST is better than that for SLA.