热带太平洋环流季节变化的数值模拟

Simulation of Seasonal Variations in the Tropical Pacific Ocean

在观测到的海表风应力和热量及淡水通量驱动下，用大气物理研究所发展的高分辨率自由表面热带太平洋环流模式对热带太平洋环流季节变化进行了数值模拟。对模拟得到的热带太平洋海面起伏、温度场和流场等季节变化分析、比较表明，模式成功地模拟了观测到的环流季节变化基本特征。其中，海面起伏中西北太平洋副热带反气旋环流在冬季最强，赤道槽在冬季和早春季强，而赤道脊和北赤道逆流槽则在秋季强；北赤道逆流在秋季强而春季弱，１５０°Ｗ附近区域赤道表层洋流流向在４至７月逆转；赤道东太平洋地区海表温度场春季增暖和秋冷却；以及次表层赤道斜温层和赤道潜流等相应的季节变化。文中通过与观测和其他模式间的比较及风场敏感性试验进一步考察了模式性能。

The IAP surface tropical Pacific Ocean general circulation model(OGCM) is used to simulate the seasonal variations in the tropical Pacific forced by the observed surface wind stress, heat and water fluxes. Analyses and comparisons of model results show successful representation of the observed sea level, temperature and currents of the tropical Pacific is strong in the winter, the epuatorial trough is srtong in the winter and the early spring, whereas the equatorial ridge and countcrcurrent trough are intense in the fall; the North Equatorial Countercurrent(NECC) is intense during the summer and fall, and the springtime reversal of equatorial surface currents along 150°W is evident; the simulated sea surface temperature(SST) variations are characterized by spring warming and fall cooling in the epuatorial eastern Pacific; and there are corresponding seasonal variations in the epuatouial thermocline and equatorial undercurrent(EUC). The model performance is further examined and verified by comparisons of model simulations with observations and by sensitivity experiments on the wind stress.