东北夏季降水的年代际特征及环流变化  

Decadal Variations of Summer Precipitation in Northeast China and the Associated Circulation

作　　者：丁婷[1] 陈丽娟[1] 崔大海 

机构地区：[1]国家气候中心中国气象局气候研究开放实验室,北京100081 [2]营口市气象局,营口115001

出　　处：《高原气象》2015年第1期220-229,共10页Plateau Meteorology

基　　金：国家重点基础研究发展计划项目(2013CB430203);公益性行业(气象)专项(GYHY201306033;GYHY201306024);国家自然科学基金项目(41275073;41205039);中国气象局短期气候预测创新团队;中国气象局气候研究开放室青年基金

摘　　要：利用1961-2012年中国东北地区91个气象站逐月降水资料、NCEP/NCAR再分析资料和海温资料,以及经验正交函数分解EOF、显著性检验等方法,分析了东北地区夏季降水的时空分布特征、年代际变化特征及相应的环流分布型变化,探讨了不同年代际背景下东北夏季降水年际变化的环流差异。结果表明,东北夏季降水存在明显的年代际变化特征,在1961 1983年(P1)期间降水偏少,19841998年(P2)期间降水偏多,1999年之后(P3)又进入偏少时段。P2与P1时段相比,东北气旋式环流和蒙古反气旋式环流异常增强,而西北太平洋副热带地区为气旋式环流异常,来自西北太平洋偏东水汽输送贡献明显。P3与P2时段相比,东北冷涡活动偏弱,东北地区东部在850 h Pa为偏北风异常,偏南水汽输送有所减弱。进一步分析证实,北太平洋年代际振荡(PDO)对于东北地区夏季降水及相关环流型的年代际变化有重要的调制作用。P1与P3同为降水偏少时段,PDO都处于负位相,东北地区反气旋式环流都偏强;然而P1时段的多雨年,水汽输送主要来自较强的夏季风偏南气流;P3时段的多雨年,水汽输送可能主要来自西北太平洋地区。Based on 91 stations monthly data,NCEP/NCAR reanalysis data and sea surface temperature data,the distribution characteristics,decadal variation of precipitation and circulation pattern w ere analyzed by empirical orthogonal function( EOF) and significant test,and the annual variations in different decades are discussed.It is found that precipitation in Northeast China in summer has large decadal variability. Less precipitation in Northeast China in summer was observed in 1961 1983( P1),more in 1984 1998( P2),and less in 19992012( P3). Compared with P1,cyclone anomaly in Northeast China,anticyclone anomaly in Mongolia,and cyclone anomaly in subtropical northw est Pacific were intensified in P2,and the contribution of easterly w ater vapor transport from Northw est Pacific was obvious. Compared with P2,Northeast cold vortex w as weaker,and anomalous northerly wind on 850 h Pa w as over the east of Northeast China in P3. Furthermore,the southerly w ater vapor transport became w eaker obviously. Pacific decadal oscillation( PDO) has a modulation effect on the decadal variation of precipitation in Northeast China and the associated circulation. Less precipitation is observed in P1 and P3. In these tw o periods,PDO are in negative phase,and anticyclone circulations in Northeast China are strong. For wet years in P1,the water vapor transport is mainly from the strong summer southerly wind,while in P3 may from the Northw est Pacific.

关 键 词：东北 降水异常 年代际变化 东北冷涡 副热带高压 

分 类 号：P426.6[天文地球—大气科学及气象学] P434