Abstract: With fresh-water fluxes at the lateral open boundaries, and with sea surface wind stress, heat fluxes, evaporation, and precipitation at sea surface, a numerical ocean model in a vertical S-coordinate was used to simulate the ocean circulation and temperature in the Northwest Pacific. The vertical S-coordinate has the advantage of not only making the model upper layers closer to the physical planes but also adapting bottom topographic change. Compared with the observed section data measured in the Northwest Pacific in 2008 by the Japanese scientists, the model calculated ocean temperate was fairly consistent with the observations in terms of pattern and quantity. The vertical S-coordinate model reproduced the climate variation of the Northwest Pacific ocean circulation and temperature well. Because the horizontal change of water depth in the model withσ-coordinate is included in the vertical layers, the upper-layer resolution is lower than that in the S-coordinate, and the horizontal distribution of initial ocean temperature includes horizontal distribution of water depth, the ocean model with a σ-coordinate cannot simulate ocean circulation and temperature as satisfactorily as the model with S-coordinate.

Key words: Northwest Pacific, vertical S-coordinate, ocean temperature, ocean circulation, numerical simulation