摘要
基于东北区域1961—2019年245站逐日降水资料,利用经验正交函数方法(EOF)、累计距平方法、滑动t检验、小波分析和相关分析等分析了东北地区初夏(6月)和盛夏(7—8月)降水的时空特征。结果表明:东北盛夏降水主要集中于东北东南部地区,初夏北部和东北部降水量也较多。东北初夏和盛夏降水EOF第一和第四模态分别表现为全区一致和自北向南负—正—负(正—负—正)的变化特征。初夏降水在1972年和1995年左右发生了共两次突变。盛夏降水分别在1966年、1983年和1998年左右发生了共3次突变。东北初夏降水在20世纪80—90年代存在显著的准6 a振荡周期,90年代后期开始准3 a周期较为显著;盛夏降水存在12 a左右的主振荡周期,且20世纪90年代之后3—4 a左右的年际尺度振荡周期显著。通过分时段探讨与降水相关的环流场特征,发现了东北初夏降水受东北冷涡的影响增强,盛夏降水由主要受西太平洋副热带高压影响转为受中纬西风带系统影响为主的新特征。
Based on the daily precipitation data of 245 weather stations in Northeast China from 1961 to 2019,the temporal and spatial characteristics of precipitation in early summer(June)and mid-summer(July and August)in Northeast China were analyzed using EOF,cumulative anomaly,moving t-test,Wavelet analysis,and correlation analysis methods.The results show that precipitation in mid-summer in Northeast China are mainly concentrated in the southeast,and more precipitation is distributed in the north and northeast in early summer.The first and fourth modes of EOF in early and mid-summer are consistent across the whole area and feature a change of negative-positive-negative(positive-negative-positive)from north to south,respectively.There are two abrupt changes of precipitation in early summer in 1972 and 1995 and three abrupt changes in mid-summer precipitation in 1966,1983,and 1998,respectively.There are prominent quasi-6-year and quasi-3-year oscillation periods in mid-summer precipitation in northeast China from the 1980s to 1990s and late 1990s,respectively.The main oscillation period of midsummer precipitation is about 12 years,and the interannual scale oscillation period for 3-4 years appears after the 1990s.With investigating the characteristics of circulation field related to precipitation on time division,it is found that the influence of Northeast Cold Vortex on the precipitation in early summer is enhanced,and the impact factors of precipitation in mid-summer transforms from the Western Pacific subtropical high to the mid-latitude westerlies system,indicating a new characteristic.
作者
林益同
赵春雨
房一禾
李倩
方晓
李璇
孙琳琳
林蓉
LIN Yi-tong;ZHAO Chun-yu;FANG Yi-he;LI Qian;FANG Xiao;LI Xuan;SUN Lin-lin;LIN Rong(Institute of Atmospheric Environment,China Meteorological Administration,Shenyang 110166,China;Shenyang Regional Climate Center,Shenyang 110166,China;Key Opening Laboratory for Northeast China Cold Vertex Research,Shenyang 110166,China;Liaoning Meteorological Information Center,Shenyang 110166,China;Chaoyang Meteorological Service,Chaoyang 122000,China;Panjin Meteorological Service,Panjin 124000,China)
出处
《气象与环境学报》
2021年第5期63-71,共9页
Journal of Meteorology and Environment
基金
国家重点研发计划项目(2018YFC1505601)
国家自然科学基金(42005037)
中国气象局创新发展专项(CXFZ2021J022、CXFZ2021Z011)
辽宁省自然科学基金-省博士科研启动基金计划项目(2019-BS-214)
中国气象局沈阳大气环境研究所开放基金项目(2020SYIAE08、2021SYIAEKFMS08)
辽宁省气象局科研课题(BA202103)共同资助。
关键词
突变
周期特征
大气环流配置
Mutation
Periodic characteristics
Atmospheric circulation configuration
