春季黑潮延伸体海洋锋区经向位移与东亚大气环流的关系

采用高分辨率的海表温度资料定义了春季黑潮延伸体北侧海洋锋区的南北位置,并采用EOF分析、相关分析、合成分析、带通滤波等方法,探讨了其南北向位置变动与高空急流、风暴轴以及后期东亚降水之间的关系。结果表明,春季黑潮延伸体北侧海洋锋区位置的南北变动存在明显的年际、年代际变化,其与6月东亚高空急流、太平洋区域风暴轴的南北位置具有很好的对应关系。当春季黑潮延伸体海洋锋区偏北时,6月东亚高空急流、太平洋区域风暴轴偏北,反之亦然。进一步的研究还表明,春季黑潮延伸体海洋锋区经向位置的变动可通过影响东亚大气环流对6月东亚地区的降水产生影响,黑潮延伸体海洋锋区偏北(南)年,6月雨带有显著的北(南)移。

The relationship between meridional displacement of the oceanic front in Kuroshio extension during spring and atmospheric circulation in East Asia

Index of the meridional displacement of the oceanic front in Kuroshio extension region during spring is defined based on high-resolution sea surface temperature dataset. We investigate its relations with the jet stream, storm track and later stage of rainfall in East Asia.Our analysis shows that there exist significantly interannual and interdecadal changes in north-south position of the oceanic front in Kuroshio extension during spring.A close relationship is found between north-south position of the oceanic front and the storm track in Pacific region, jet stream in East Asia. As the oceanic front is inclinable to the north in spring, storm track and jet stream shift northward in June accordingly, and vice versa. Further research also reveals that atmospheric circulation in East Asia can be influenced by the displacement of oceanic front,resulting in precipitation anomaly in June. In correspondence with the northerly (southerly) position of oceanic front, rain band migrates northward (southward) perceptibly.