摘要
基于改进的1/30°分辨率的南海业务化预报系统,利用集合最优插值(En OI)同化方法对南海北部中尺度涡进行了同化模拟研究。模拟结果准确再现了2013年冬季发生在台湾岛西南海域的一对冷、暖中尺度涡的生成及传播过程。分析暖涡和冷涡成熟时期的垂向结构发现:暖涡中心温跃层深度超过200 m,而冷涡中心温跃层深度小于150 m;暖涡和冷涡经向和纬向流速均存在不对称性,相邻一侧流场强度明显偏强,对应较强的水平流速切变。上述特征与同时期南海中尺度涡观测实验结果基本一致。对暖涡和冷涡生成机制的分析印证了暖涡是由黑潮流套脱离生成的观点,同时指出冷涡是暖涡北侧较强的气旋式流速切变及西南向海流产生的离岸输运共同作用产生的。
Based on the improved South China Operational Forecasting System of 1/30°resolution, the Ensemble Optimal Interpolation(En OI)assimilation was applied to the model for simulating the mesoscale eddies in the northern South China Sea(SCS). The simulation results accurately reproduce the generation and propagation process of the paired eddies occurred in the southwest of Taiwan during the winter of 2013. The vertical structure of the paired eddies during their mature period were analyzed, the results suggested that the thermocline depth of the warm eddy center is more than 200 m, and the thermocline depth of the cold eddy center is less than 150 m.The meridional and zonal velocities of the paired eddies were asymmetric, and the adjacent side flow showed stronger with the corresponding level of strong velocity shear. All the above characteristics were in agreement with the results of South China Sea Mesoscale Eddy Experiment(S-MEE)during the same period. In addition,the generation mechanism analysis of the paired eddies confirmed that the warm eddy shed from the Kuroshio loop, and pointed out that the cold eddy originated from the combined action of strong cyclonic shear on the north side of warm eddy and offshore transport caused by the southwest currents.
出处
《海洋预报》
2017年第5期1-15,共15页
Marine Forecasts
基金
国家重点基础研究发展计划项目(2014CB745004)
“全球变化与海气相互作用”专项(No.GASI-IPOVAI-06)
国家自然科学基金项目(41376016)
关键词
中尺度涡
数值模拟
数据同化
台湾西南
mesoscale eddy
numerical simulation
data assimilation
southwest of Taiwan
