The interdecadal trend and shift of dry/wet over the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO)
The interdecadal trend and shift of dry/wet over the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO)
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DOI：
10.1007/s11434-007-0284-z
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发表时间：
2007-08-01
影响因子：
--
通讯作者：
Ma ZhuGuo
中科院分区：
文献类型：
--
作者：
Ma ZhuGuo
利用月降水量和月平均气温资料，通过计算地表湿润指数，分析了1951 - 2005年华北中部地区干湿变化趋势和变化与太平洋年代际振荡的关系。结果表明，在分析期内，土壤干燥化趋势明显，且存在突变现象。结果表明，华北中部地区从20世纪70年代中后期至今存在一个持续偏暖的偏少降水期，并在1951-2005年存在一个由湿向干的转换过程。该转折点位于20世纪70年代中后期，应与大尺度气候背景的转移变化有关。相关分析发现，PDO指数与该地区的SAT、降水量和SWI之间存在显著的相关关系。相关分析表明，PDOI的正位相（暖PDO位相）与气候变暖、降水偏少和干旱期相对应，负位相与低SAT、降水偏多和湿润期相对应。各阶段的持续时间超过25年。北太平洋海温的年代际变化是华北中部地区干湿变化趋势和年代际变化的可能原因之一。
Based on monthly precipitation and monthly mean surface air temperature (SAT), the dry/wet trends and shift of the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO) from 1951 to 2005 have been analyzed through calculating surface wetness index (SWI). The results indicate that there was a prominent drying trend and an abrupt change in the analysis period. A persistent warming period with less precipitation from the mid and late 1970s to present was found, and a shift process exists from the wet to the dry in the central part of North China during 1951-2005. The transition is located in the mid to late 1970s, which should be related to the shift variation of large-scale climate background. The correlation analysis has brought about a finding of significant correlativity between PDO index (PDOI) and SAT, precipitation and SWI in this region. The correlation exhibits that the positive phase of PDOI (warm PDO phase) matches warming, less precipitation and the drought period, and the negative PDOI phase corresponds to low SAT, more precipitation and the wet period. The duration of various phases is more than 25 years. The decadal variation of sea surface temperature (SST) in the North Pacific Ocean is one of the possible causes in forming the decadal dry/wet trend and shift of the central part of North China.