摘要
应用奇异谱(SSA)方法分析了华北地区降水的准周期信号及其阶段性变化特征,结果表明,华北地区月降水序列的年际振荡信号较强,占总方差的44.7%,显著振荡周期分别有17个月(准1～2 a)、30个月(准2～3 a)、60个月(准5 a)和11个月(准1 a),不同分区降水的准周期振荡信号各有差异.各种准周期振荡随时间的长期演变亦很明显且各不相同.奇异交叉谱(SCSA)诊断表明,华北地区降水的年际振荡与Nino区海温的准周期信号存在着显著的耦合关系,且这种耦合关系随时间是变化的,表现出耦合振荡强度的阶段性变化和耦合位相随时间的改变.各分区降水与不同Nino区海温的显著耦合周期信号及其随时间的长期演变各具特色,体现了华北地区降水对Nino区海温异常响应的复杂性.
The quasi-periodic signals and its inter-decadal changes of the monthly rainfall anomaly series are diagnosed over North China by means of singular spectrum analysis （SSA）. The results show that the inter-annual oscillations of the rainfall series are strong accounting for about 44.7 % of the total variance, and significant oscillation periods are 17 months （ quasi-1 - 2 years）, 30 months （ quasi-2 - 3 years） ,60 months （ around 5 years） and 11 months （ quasi-1 year）. The quasi-periodic signals display different features in different sub-division, and their long-term changes are also distinct and different from each other. The singular cross spectrum analysis （SCSA） suggests that there exist evident coupling relations between the inter-annual oscillations of the precipitation series over North China and the quasi-periodic signals of the sea surface temperature （SST） in Nino regions, and the relations vary with time, showing the phased change feature of the coupled oscillatory intensity and the time-varying feature of coupling phase. The dominant couple periodic signals between various sub-divisions rainfall and the SST over different Nino regions, display different features in defterent sub-divisions reflecting the complicacy of responses of the precipitation over North China to the SST anomaly over Nino regions.
出处
《南京气象学院学报》
CSCD
北大核心
2005年第6期770-777,共8页
Journal of Nanjing Institute of Meteorology
基金
国家科技部社会公益类资助项目(2002DIB20067)
关键词
华北地区降水
准周期信号
耦合振荡
rainfall over North China
quasi-periodic signals
coupled oscillations
