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东北夏季降水的年代际特征及环流变化

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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,1984-1998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850hPa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.
Decadal Variations of Summer Precipitation in Northeast China and the Associated Circulation
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 were analyzed by empiri-cal 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 1999-2012(P3).Compared with P1,cyclone anomaly in Northeast China,anticyclone anomaly in Mongolia,and cyclone anomaly in subtropical northwest Pacific were intensified in P2,and the contribution of easterly water vapor transport from Northwest Pacific was obvious.Compared with P2,Northeast cold vortex was weaker,and anomalous northerly wind on 850 hPa was over the east of Northeast China in P3.Furthermore,the southerly water vapor transport became weaker 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 two 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 Northwest Pacific.

Northeast ChinaPrecipitation anomalyDecadal variationNortheast cold vortexWestern Pacific subtropical high

丁婷、陈丽娟、崔大海

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国家气候中心中国气象局气候研究开放实验室,北京100081

营口市气象局,营口115001

东北 降水异常 年代际变化 东北冷涡 副热带高压

国家重点基础研究发展计划项目公益性行业(气象)专项公益性行业(气象)专项国家自然科学基金国家自然科学基金

2013CB430203GYHY201306033GYHY2013060244127507341205039

2015

高原气象
中国科学院寒区旱区环境与工程研究所

高原气象

CSTPCDCSCD北大核心
影响因子:2.193
ISSN:1000-0534
年,卷(期):2015.34(1)
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