Baseline Evaluation of a Pressure Coordinate Ocean Model (PCOM 1.0)

An 800-year integration has been carried out to evaluate the baseline performance of a mass conserved, Pressure Coordinate Ocean Model (PCOM1.0) against observational and reanalyzed data, using the main metrics of the Coordinated Ocean-ice Reference Experiments (COREs). In general, the sea water temperature, salinity, and ocean circulations simulated by PCOM1.0 are comparable with those of the COREs models. The strength of simulated Atlantic meridional overturning circulation reaches 18 Sv (1 Sv=10⁶ m³ s^-1) near 45°N, close to the estimated values based on observations. The bias for the sea surface temperature mainly derives from the major frontal zones, such as the Kuroshio area in the North Pacific Ocean and the Gulf Stream in the North Atlantic Ocean. In the tropical Pacific Ocean, PCOM1.0 systematically exhibits an overly deep thermocline compared with observations. In the Southern Ocean, the simulated volume transport through Drake Passage is about 130 Sv, closer to observations than results from most of the COREs models and the reanalyzed data.