河南省气候变化与北极涛动的多时间尺度相关

Multi-Time Scale Correlations between Climate Variations and the Arctic Oscillation in He′nan Province

将交叉谱与小波变换方法相结合,采用交叉小波分析方法,分析了冬、夏季北极涛动指数距平（ΔIAO）、河南省降水距平（ΔR）和气温距平（ΔT）序列的时频结构及其联合统计特征,讨论了近55年来河南省气候变化与北极涛动之间的多时间尺度相关。结果表明：冬、夏季ΔIAO、ΔR和ΔT都存在准2年、4年、6～8年和11～22年左右的周期信号。冬季ΔR与ΔIAO之间的显著相关表现在准2年和14～22年尺度共振周期上,年代际尺度正相关振荡的凝聚性最强且为全时域分布;冬季ΔT与ΔIAO的显著正相关表现在2～4年和6～10年尺度共振周期上,时域中相关振荡存在局部化特征;年代际尺度上ΔR与ΔIAO的相关显著性高于ΔT与ΔIAO的相关而年际尺度上ΔT与ΔIAO的相关比ΔR与ΔIAO的相关更显著,表明冬季AO对河南省降水和气温变化的影响机制不同。夏季ΔR与ΔIAO之间的显著相关表现在准2年、4～6年、6～8年和16年左右尺度共振周期上,以6～8年尺度正相关振荡凝聚性最强;夏季ΔT与ΔIAO的相关显著性较低,仅在年际尺度周期上局部时域中有所表现;夏季AO主要通过影响东亚季风强度对河南省降水和气温变化产生间接影响。

The cross spectrum analysis combining with the wavelet transform analysis method is adopted to study the time-frequency characteristics and multi-time scale correlations between the anomaly series of precipitation（ΔR）,temperature（ΔT） and the Arctic Oscillation Indices（ΔIAO） in He′nan Province in summer and winter of the last 55 years.The results show that there are periodic variations of quasi-biannual,4 a,6～8 a,11～22 a in the winter and summer ΔIAO,ΔR and ΔT.The significance of correlations between ΔR and ΔIAO in winter present on the syntonic periods at scales of quasi-biannual and 14～22a,and the cross-wavelet coherence of the positive correlation distributing in all time space on the interdecadal timescale is the highest.The winter ΔT and ΔIAO exhibits significant correlation at scales of 2～4 a and 6～10a and localization characteristics in time space are obviously.The significance of correlations between ΔR and ΔIAO is higher than the significance of correlations between ΔT and ΔIAO on the interdecadal timescale,but contrary on the interannual timescale.It shows that effects of the winter AO on the variations of precipitation and temperature in He′nan province are different.The significance of correlations between ΔR and ΔIAO in summer display on the syntonic periods at scales of quasi-biannual,4～6 a,6～8 a and about 16 a,and the most significant correlation present on the scale of 6～8 a.The cross-wavelet coherence of the correlations between ΔT and ΔIAO in summer is lower,only distributing in some of the time space on the interannual timescale.The effects of the summer AO on the variations of precipitation and temperature in He＇nan province are indirect by changing the intensity of the East Asian monsoon.