热带对流活动及其与ENSO关系的非线性特征

Nonlinear Characteristics of Relationship between Convective Activity over Tropics and ENSO

摘要:

用非线性主成分分析方法和NCAR/NCEP长波辐射资料(OLR),研究了热带对流异常及其与ENSO的关系。结果表明热带对流活动在时空上呈现出明显的非线性特征,它是热带对流活动对ENSO的非线性响应;热带对流异常的强度在El Nino时期比在La Nina时期强,且异常的中心位置偏东,表现出明显的时空上的不对称性。

Abstract:

Based on the NCEP/NCAR reanalysis data of OLR,Nonlinear Principal Component Analysis(NLPCA) are used to research the convective activity over the tropics and its relationship with ENSO.The results show that more nonlinear characteristics of time-space structer are found by using NLPCA than by linear analysis techniques.Such nonlinear characteristics may reflect the nonlinear relationship between tropical convective activities and ENSO.The intensity of OLR anomalies is stronger in the average El Nino period than in the average La Nina period.And the center of OLR anomalies in the averger in the average El Nino period tends to lie at a position east of that in the average La Nina period,thus showing the spatial asymmetry of OLR in the average warm and cold phases of ENSO.