我国西北地区气温变化与Nio3区SST的关系及其稳定性分析

Relationship between SST in Nio3 and Air Temperature over Northwest China,Together with Its Stability

根据1956—2005年中国西北地区72个观测站的月平均气温资料,分析了气温的空间分布特征,利用相关分析、滑动t检验、小波分析和小波凝聚谱等方法,探讨了Nio3区SST与西北地区气温的关系及其稳定性.结果表明:一致性异常分布是西北地区气温变化的最主要空间模态,第一模态时间系数与Nio3区SST有着较好的相关关系.在典型的ENSO暖状态,西北地区气温偏高,在典型的ENSO冷状态则情况相反.西北地区气温和Nio3区SST关系的稳定性分析表明,气温和SST之间在1～5a变化周期上存着较好的相关关系,但这种相关关系并不稳定,存在着年代际变化:1956—1970年正相关较好,1992—2005年反相关较好,而在1971—1991年二者相关关系较差.

Based on the monthly mean temperatures of 72 meteorological stations in Northwest China during 1956--2005, air temperature distribution was analyzed. At the same time, by correlation analysis, moving t-test and cross-wavelet transform, the relationship between air temperature in Northwest China and ENSO, together with its stability, were also analyzed. The main results are as follows： The consistent abnormity temperature distribution is the principal mode of air temperature variation. Time series of the leading mode of EOF has good relationship with ENSO. This relationship manifests that in the typical warm phase of ENSO, air temperature in Northwest China is higher, and vice versa. Air temperature in Northwest China has good relationship with ENSO for the changing periods of 1-5 a, but it is not always true. There were good positive and negative correlations during 1956--1970 and 1992--2005, respectively, while, the correlation was poor during 1970--1991.