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干旱区地理 ›› 2017, Vol. 40 ›› Issue (2): 239-247.

• 气候与水文 •    下一篇

西北地区东部夏季水汽输送特征及其与降水的关系

赵光平1, 姜兵1, 王勇1, 沈新勇1,2   

  1. 1. 南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏 南京 210044;
    2. 中国科学院大气物理研究所云降水物理与强风暴重点实验室, 北京 100029
  • 收稿日期:2016-11-12 修回日期:2017-02-17 出版日期:2017-03-25
  • 作者简介:赵光平(1962-),男,山东牟平人,正研级高级工程师,主要从事天气预报业务及灾害性天气防灾减灾对策研究Email:zgp@nuist.edu.cn
  • 基金资助:

    国家重点基础研究发展计划973项目(2015CB453201,2013CB430103);国家自然科学基金项目(41475090,41375058,41530427)

Characteristics of summer water vapor transport in the eastern Northwest China and their relationships with precipitation

ZHAO Guang-ping1, JIANG Bing1, WANG Yong1, SHEN Xin-yong1,2   

  1. 1. Key Laboratory of Meteorological Disaster, Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China;
    2. Key Laboratory of Cloud-Precipitation Physics and Severe Storms, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
  • Received:2016-11-12 Revised:2017-02-17 Online:2017-03-25

摘要: 采用ERA Interim 再分析资料和160 站逐月站点降水资料,运用经验正交函数(EOF)分析、合成分析等方法揭示了西北东部3 个分区的水汽输送的区域气候特征、与降水EOF气候模态相对应的整层水汽输送特征以及降水偏多(少)年的水汽输送异常特征。结果表明:西北地区东部夏季经向水汽输送的大值区处于900 hPa~800 hPa 高度上;纬向水汽输送大值位于700 hPa~500 hPa 高度上。对西北东部降水做EOF 分析,第一模态为全区一致型,与降水相对应的西风影响区主要盛行西风水汽输送,季风边缘区的南部盛行西南风水汽输送;第二模态为东南-西北型,东风、东北风水汽输送流入西北东部地区;第三模态为东北-西南型,西风和西北风水汽输送将水汽带到西风影响区内。

关键词: 西北地区东部, 水汽输送, EOF分析, 合成分析

Abstract: On the basis of ERA Interim reanalysis data and monthly precipitation observation station data of 160 stations over the eastern northwest China(32.5°N-42.5°N, 100°N-112.5°N)during 1979-2015, the regional climatic characteristics of water vapor transportation over eastern northwest China, characteristics of vertically integrated water vapor transportation corresponding with the EOF modes of precipitation, characteristics of geopotential height and water vapor transportation anomaly during strong(weak) precipitation years were revealed through empirical orthogonal function(EOF)analysis, composite analysis methods. The results show that the strongest summer latitudinal vapor transportation is at 700-500 hPa, and the strongest summer longitudinal vapor transportation is at 900-800 hPa over the eastern northwest China. The first EOF mode of eastern northwest China precipitation is consistent over the whole area. Corresponding to the first precipitation mode, there is a cyclonic anomaly to the east of Lake Baikal and an anticyclonic anomaly over south-east China and the water vapor transported by west wind almost prevails the whole area. Water vapor transported by wet south-west wind from prevails to the south of Monsoon Fringe. The second EOF mode of precipitation shows southeast-northwest pattern. Corresponding to the second EOF mode, an anticyclonic anomaly centers around Siberia and the westerly wind area is located to the north of the anticyclonic anomaly. Water vapor is mainly transported by easterly wind. The strongest precipitation area is around the east boundary because the water vapor transported through east boundary is reduced at the transportation process. There is a cyclonic anomaly around the Yellow Sea. Qinghai-Tibet Plateau and the monsoon fringe area are to the north-west of the cyclonic anomaly. Water vapor is mainly transported by north-east wind from the ocean to the east of China. The third mode shows northeast-southwest pattern. Corresponding to this mode, there is a cyclonic anomaly in the Northeast of China and the water vapor is transported to the east of Northwest China by westerly wind and north-westerly wind to the south of the cyclonic anomaly. The composite of geopotential height and water vapor fluxes between the strong precipitation years and weak precipitation years shows that an anticyclonic anomaly is over Southeast China, which benefits the south-west water vapor to come into the monsoon fringe. At the same time, there is a cyclonic anomaly to the east of Lake Baikal providing westerly and north-westerly water vapor transportation, and the convergence is strengthened as well. The circulation configuration is similar to the 500-hPa geopotentia height field and water vapor transportation field regressed to the first EOF mode of precipitation.

Key words: eastern northwest China, water vapor transport, EOF, composite analysis

中图分类号: 

  • P426