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	中国北方夏半年极端干期的时空变化特征
其他题名	Spatial and Temporal Variation Characteristics of the Extreme Dry Spells in Summer Half Year of Northern China
	刘莉红; 翟盘茂; 郑祖光
来源期刊	高原气象
ISSN	1000-0534
出版年	2010
卷号	29 期号:2 页码:403-411
中文摘要	利用1951--2004年我国北方348个测站的夏半年逐日降水资料, 首先整理出各站点的极端干期日数和无雨总日数两个序列, 得到极端干期日数的空间分布, 并将北方划分为A、B、C 3个区, 其中 A、B 2个区相对湿润, C区则相对干旱和半干旱, 这种分布与地理环境有密切的联系. 然后建立这3个区夏半年极端干期以及无雨总日数的时间序列, 采用经验模态分解(EMD)方法, 分析极端干期序列的多尺度振荡结构以及多年变化的总趋势. 结果显示, 北方各区夏半年极端干期变化主要由前2个较高频的本征模态函数(IMF)分量构成, 这表明3~4年和6~7年的变化对整个极端干期的变化起主要作用. 对较低频分量和总趋势的分析表明, 近54年来东北和华北大部分相对湿润的地区极端干期延长, 有变干的趋势;北方主要干旱半干旱地区的极端干期变短, 干旱有所缓解. 近10~20年来整个北方极端干期日数增加, 干旱化加剧, 但西北局部干旱地区的极端干期在缩短, 干旱有所缓解. 这说明, 分析的时--空尺度不同, 得到的结果会有所不同.
英文摘要	Daily precipitation data at 348 stations in summer half year (from April to September) of northern China from 1951 to 2004 are selected to construct two types of time series of the days of the extreme dry spells and the total rainless days. According to the space distribution of the extreme dry spells acquired, northern China can be divided into 3 regions: A, B and C, in which A and B are relative wetter regions, while region C is arid and semi-arid regions. The distribution in each region is closely related to that of geography surrounding. Then time series of period of the extreme dry spells and total rainless days are constructed for each region and then the empirical mode decomposition (EMD) method is used to analyze multi-time scale vacillation in the series, respectively. The results show that the variation of extreme dry spell is mainly characterized by 2 higher frequency components of intrinsic mode function(IMF), i.e. vacillations with the periods of 3~4 years and 6~7 years play important roles. In the recent 54 years, lower frequency vacillation components and trends show that the period of extreme dry spell is increasing more in the wetter regions of northeast China and trends to more dry situation, while the dry situation relaxed because of shortening of extreme dry spell arid and semi-arid regions, while in recent 10~20 years, the period of extreme dry spells is increasing in northern China and thus the drought intensifies. Extreme dry spells is shorten in local drought region of northwest China, and the dry spell situation relax. It shows that the result would be different due to the different time-space scales taken result in analysis.
中文关键词	中国北方 ; 极端干期 ; 区域特征 ; 经验模态分解 ; 振荡变化
英文关键词	IMF Northern China Extreme dry spell Characteristics of regional variation Empirical mode decomposition IMF Vacillation
类型	Article
语种	中文
国家	中国
收录类别	CSCD
WOS类目	Meteorology & Atmospheric Sciences
WOS研究方向	Meteorology & Atmospheric Sciences
CSCD记录号	CSCD:3913689
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/225206
作者单位	刘莉红, 中国气象局培训中心, 中国气象局培训中心, 北京 100081, 中国.; 郑祖光, 中国气象局培训中心, 中国气象局培训中心, 北京 100081, 中国.; 翟盘茂, 中国气象局国家气候中心, 中国气象局国家气候中心, 北京 100081, 中国.
推荐引用方式 GB/T 7714	刘莉红,翟盘茂,郑祖光. 中国北方夏半年极端干期的时空变化特征[J],2010,29(2):403-411.
APA	刘莉红,翟盘茂,&郑祖光.(2010).中国北方夏半年极端干期的时空变化特征.高原气象,29(2),403-411.
MLA	刘莉红,et al."中国北方夏半年极端干期的时空变化特征".高原气象 29.2(2010):403-411.