Influences of the Kuroshio seasonal variation on the oceanic subcirculation

The Kuroshio valley is one of the most active airsea heat exchange oceanic regions in the global oceans, and the heat carried by it plays an important role in the local airsea interaction. The early studies in 1950-1960s found the relationship between the winter Kuroshio sea surface temperature and the summer precipitation over the Yangtse River valley. A 2.5－layer oceanic model is employed to investigate the influences of the Kuroshio seasonal variation on the oceanic subcirculation from a dynamic view. Under the forcings of the heat source in winter as well as the heat sink in summer, the peak of the thermocline temperature anomaly is in the spring, lagging one season behind that of the heat source. The seasonal peak of the mixedlayer temperature anomaly is also in the spring. The anomalies of the mixedlayer temperature are positive from the winter to the summer and are negative in the autumn, which is consistent to the results of observational data. The mixedlayer temperature anomalies are generally equal to the thermocline temperature anomalies in the spring and are higher than those in the others seasons. The subcirculations of the thermocline and mixed layers present the anticyclones in the winter shifting to the cyclones in the summer. These situations are conductive to the heat transfer to the seas nearby the eastern China in the summer.