SVD相空间分析方法及其在海气耦合关系中的初步应用

SVD Phase Space Analysis and Its Preliminary Application to Sea-Air Coupling Relationship

利用非线性动力学中的相空间概念和场诊断分析中的SVD技术,提出了一种SVD相空间分析方法。应用该方法研究了热带太平洋ElNi no区SST与东亚500hPa环流场的关系。结果表明:这种SVD相空间分析,优于EOF相空间分析,它不仅能在两个场耦合联系的基础上分析两场自身的变化过程和状态特征,而且能够揭示两场之间的内在相互联系;前期冬半年东亚冬季风异常偏强(弱)时,将导致未来ElNi no(LaNi na)事件的发生;前期ElNi no(LaNi na)事件,将导致未来冬半年东亚冬季风异常弱(强);由此建立了东亚冬季风与ElNi no(LaNi na)事件相互作用的概念模型,指出了东亚冬季风异常变化与ElNi no(LaNi na)事件互为双方发生发展的重要机制。

Using the Singular Value Decomposition (SVD) technique and phase space analysis, the relationship between SST in El Nio region over the tropical Pacific and 500 hPa hight field in East Asia is studied. The result shows that there is closely asynchronous coupling relationship between the 500 hPa geopotential height field in winter half year and SST in Nio 1～4 regions in autumn. The first modes derived from SVD indicate the key timespace correlation characteristics of the two fields. When East Asian winter monsoon is stronger(weaker) in preceding winter, El Nio(La Nia) event will occur. East Asian winter monsoon has important effect on ENSO cycle. When El Nio(La NiKn～Da) event appears, East Asian winter monsoon will be weaker(stronger) in following winter. El Nio(La Nia) event has also very important effect on East Asian winter monsoon. According to the trigger actions of stronger (weaker) East Asian winter monsoon in preceding winter and previous El Nio (La Nia) event the conceptual model of the interaction between East Asian winter monsoon and El Nio(La Nia) events is set up. Furthermore, it is pointed out that the anomalous variation of East Asian winter monsoon and the effect of ENSO cycle are an important mechanism for the occurrence and development of the other party of the two parties, respectively. In addition, it is presented that a way of phase space analysis based on SVD. It can be not only to analyze the varying processes and anomalous feature of fields themselves but also to reveal the internal interrelation of the two fields on the basis of coupling relation of the two fields.