近50年来长江入海径流量对太平洋年代际震荡变化的响应  

Response of discharges from Changjiang River on Pacific Decadal Oscillation in the past 50 years

作　　者：张瑞[1,2,3] 汪亚平[2] 潘少明[2] 

机构地区：[1]淮海工学院测绘工程学院,江苏连云港222005 [2]南京大学海岸与海岛开发教育部重点实验室,江苏南京210093 [3]江苏省海洋资源开发研究院,江苏连云港222001

出　　处：《海洋通报》2011年第5期572-577,共6页Marine Science Bulletin

基　　金：国家重点基础研究发展规划项目(2002CB412401);国家自然科学基金(40106009;40576040);淮海工学院科研启动基金(KQ09041)

摘　　要：太平洋年代际震荡(Pacific Decadal Oscillation)是类似于ENSO型的具有年代际时间尺度变化的太平洋气候变率。PDO既对长期的气候变化趋势产生扰动,又会对年际变化事件(如ENSO)产生重要影响,可使ENSO事件的频率和强度改变,以致影响到ENSO和季风的关系。通过对百年来的PDO数据进行HHT分析,得到8个IMF和1个趋势项,这表明PDO存在显著的15 a、30 a、60 a的年代际变化,并且还有准2 a、6 a的年际波动。同时对近50年来的长江入海月均径流量序列也进行HHT分析,得到7个IMF和1个趋势项,结果表明长江入海月均径流量序列存在有明显的季节变化,显著的准2 a、4 a、8 a的年际变率,和显著的16 a、22 a的年代际变率。并且对近50年来的长江入海月均径流量序列和PDO序列的EMD分量进行相关性分析,分析得知两者在年代际变化中有较高的相关性,这表明在长时间尺度的年代际变化中PDO对长江入海径流有着显著地影响。Pacific Decadal Oscillation（PDO） is a long-term ENSO-like variability of the north Pacific.The index of PDO is denoted by the first principal component of EOF of the north Pacific SST.The PDO not only disturb the long-live trend of climate changes,but also influences significantly annual climate change（e.g.ENSO）.The relationship between ENSO and monsoon also is influenced by PDO.Hilbert-Huang Transform（HHT） is used to analyze PDO over one hundred years to obtain 8 IMF and 1 residual.The results show that PDO has the quasi-2 and 6-year variability as well as significant quasi-15 and 30 and 60-year multi-decadal timescales.The discharges from Changjiang River in the last 50 years exit 7 IMF and 1 residual,which indicate that water discharges have seasonal change,quasi-2 and 4 and 8-year variability as well as significant 16 and 22-year multi-decadal variability.It is found that the good correlations between the discharges and PDO exit on the low frequency of long cycle multi-decadal timescales.Moreover,the relationship of both residuals is also significant.It is indicated that PDO influences water discharge from Changjiang River on long-term multi-decadal timescales.

关 键 词：PDO EMD 径流量 长江 

分 类 号：TV148[水利工程—水力学及河流动力学]