Evaluation of the North Indian Ocean forecasting system of NMEFC

Abstract With the growing demands for North Indian Ocean forecast, National Marine Environmental Forecasting Center (NMEFC) build a North Indian Ocean Forecasting system. This article gives a description of the system set-up, and the evaluation of the result from January 2022 to October 2022 of the system. The RMSEs of temperature, salinity and variation of velocity from NMEFC-NIOFS and RAMA buoys data are compared. Further more, six representative global forecasting systems are evaluated and compared with it based on IV-TT class4 metrics for the same region. Results shows that vertical distribution and variation of temperature and salinity are well reproduced by NMEFC-NIOFS. The maximum RMSE of temperature is observed at depths near thermocline, which suggests the uncertainty of the thermocline simulation. The maximum RMSE of salinity is observed at sea surface, which is possibly related to the surface processes such as evaporation/precipitation or surface salinity assimilation. Comparing to other six global forecasting system, the RMSE of SST from NMEFC-NIOFS performs best. The SSS, vertical sea temperature and salinity ranks in the middle which have space for future improvements.