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陕西8月降水时空分布特征及成因

肖科丽1,2方建刚1王娜1蔡新玲1   

  1. 1.陕西省气候中心,陕西西安710015; 2.陕西省气象培训中心,陕西西安710015
  • 出版日期:2016-02-29 发布日期:2016-02-29
  • 通讯作者: 方建刚(1960- ),男,陕西咸阳人,正研级高级工程师.
  • 作者简介:肖科丽(1964-),女,高工,从事气候与气候变化分析研究.E-mail:xklnew @126.com
  • 基金资助:

    中科院知识创新工程重要方向项目(KZCX2-EW-114)、中科院—国家外专局创新团队国际合作伙伴计划(KZZD-EW-TZ-03)及陕西省气象局2013年研究型业务重点科研项目(2013Z-5,2013Z-6)共同资助

Spatial and Temporal Distribution of Precipitation in August in Shaanxi Province and Causes Analysis


XIAO Keli 1,2FANG Jiangang1WANG Na1CAI Xinling1   

  1. 1. Shaanxi Climate Center, Xi’an 710015, China;
    2. Shaanxi Meteorological Society, Xi’an 710015,China
  • Online:2016-02-29 Published:2016-02-29

摘要:

基于1961~2013年陕西月降水观测资料和NCEP/NCAR再分析资料,采用EOF和REOF方法分析了陕西8月降水的区域气候特征,并用合成分析方法讨论了陕西8月一致多雨和少雨年的大气环流特征。结果表明:陕西8月降水的EOF分析前3个特征向量场较好地反映了降水区域分布特征,而REOF分析则显示了陕西8月降水区域差异特征。陕西8月一致多雨年南亚高压范围偏大、强度偏强,西太平副热带高压强度偏强、位置偏北偏西,欧亚中高纬度西风带乌拉尔山长波脊偏强,青藏高原低值系统活跃,印缅槽偏深;一致少雨年我国北方大部主要受大陆带状高压控制,相应的对流层低层高原东侧为偏北风距平,这支偏北风距平减弱了偏南风的水汽向北输送。

关键词: 气候异常, 时空特征, 大气环流, 陕西

Abstract:

Based on NCEP/NCAR reanalysis data and monthly precipitation data in Shaanxi Province from 1961 to 2013,the spatial and temporal distribution characteristics of August precipitation were analyzed by using EOF and REOF analysis methods, and the atmospheric circulation characteristics in rainy years and dry years in Shaanxi were discussed by using composite analysis method. The results showed that the first three loading vector fields could reflect the whole anomaly structures of August rainfall in Shaanxi, and the rotated loading vector fields represented regional difference characteristics of Shaanxi August precipitation. When South Asia high was stronger and its range was larger, the western Pacific subtropical high was obviously stronger and extended abnormaly northward and westward, the long wave ridge over the Ural Mountains was stronger, and low-value system over the Tibetan Plateau was more active and the India-Burma trough was deeper, there was more rain in August of Shaanxi. Whereas, when the most part of Northern China was controlled by mainland zonal high, and there was abnormal north wind in the east side of the plateau in lower troposphere, which weakened southerly wind transporting moisture to northward, so there was less rain in August of Shaanxi.

Key words: climate anomaly, spatial-temporal feature, atmospheric circulation, Shaanxi Province

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