中国物理B ›› 2012, Vol. 21 ›› Issue (11): 119201-119201.doi: 10.1088/1674-1056/21/11/119201

• GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS • 上一篇    下一篇

A decomposition study of moisture transport divergence for inter-decadal change in East Asia summer rainfall during 1958–2001

戴新刚a, 汪萍b, 张凯静c   

  1. a Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China;
    b Chinese Academy of Meteorological Sciences, Beijing 100081, China;
    c Qingdao Meteorological Service, Qingdao 266003, China
  • 收稿日期:2012-01-18 修回日期:2012-05-30 出版日期:2012-10-01 发布日期:2012-10-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 40775048 and 41075058) and the Special Scientific Research Fund of Public Welfare Profession of China (Grant No. GYHY201106016).

A decomposition study of moisture transport divergence for inter-decadal change in East Asia summer rainfall during 1958–2001

Dai Xin-Gang (戴新刚)a, Wang Ping (汪萍)b, Zhang Kai-Jing (张凯静 )c   

  1. a Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China;
    b Chinese Academy of Meteorological Sciences, Beijing 100081, China;
    c Qingdao Meteorological Service, Qingdao 266003, China
  • Received:2012-01-18 Revised:2012-05-30 Online:2012-10-01 Published:2012-10-01
  • Contact: Wang Ping E-mail:pwang@cams.cma.gov.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 40775048 and 41075058) and the Special Scientific Research Fund of Public Welfare Profession of China (Grant No. GYHY201106016).

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摘要： In this paper, we report on the results of an investigation into inter-decadal changes in moisture transport and divergence in East Asia for the two periods 1980-2001 and 1958-1979. The aim is to explore the mechanism of summer rainfall change in the region after the abrupt change. The relevant changes are calculated using ERA-40 daily reanalysis datasets. The results show that both stationary and transient eddy moisture transports to the Chinese mainland have declined since the abrupt change in atmospheric general circulation in the late 1970s, leading to more rainfalls in South China and less in the North. The anomalous rainfall pattern coincides well with anomalous large-scale moisture divergence in the troposphere, of which stationary-wave or monsoon transport is dominant, in comparison with the contribution of the transient eddies. Furthermore, their divergences are found to be in opposite phases. In addition, meridional divergence is more important than its zonal counterpart, with an opposite phase in East Asia. Abnormal zonal moisture convergences appear in northwestern and northeastern parts of China, and are related to the excess rainfalls in these regions. An increase in transient eddy activity is one of the major mechanisms for excess rainfall in northern Xinjiang. Consequently, the anomalous rainfall pattern in East Asia results from a decline of East Asian monsoon after the abrupt change, while the rainfall increase in northwestern China involves anomalies of both stationary waves and transient eddies on boreal westerly over the mid- and high latitudes.

关键词: inter-decadal climate change, moisture transport, transient eddy, East Asian monsoon

Abstract: In this paper, we report on the results of an investigation into inter-decadal changes in moisture transport and divergence in East Asia for the two periods 1980-2001 and 1958-1979. The aim is to explore the mechanism of summer rainfall change in the region after the abrupt change. The relevant changes are calculated using ERA-40 daily reanalysis datasets. The results show that both stationary and transient eddy moisture transports to the Chinese mainland have declined since the abrupt change in atmospheric general circulation in the late 1970s, leading to more rainfalls in South China and less in the North. The anomalous rainfall pattern coincides well with anomalous large-scale moisture divergence in the troposphere, of which stationary-wave or monsoon transport is dominant, in comparison with the contribution of the transient eddies. Furthermore, their divergences are found to be in opposite phases. In addition, meridional divergence is more important than its zonal counterpart, with an opposite phase in East Asia. Abnormal zonal moisture convergences appear in northwestern and northeastern parts of China, and are related to the excess rainfalls in these regions. An increase in transient eddy activity is one of the major mechanisms for excess rainfall in northern Xinjiang. Consequently, the anomalous rainfall pattern in East Asia results from a decline of East Asian monsoon after the abrupt change, while the rainfall increase in northwestern China involves anomalies of both stationary waves and transient eddies on boreal westerly over the mid- and high latitudes.

Key words: inter-decadal climate change, moisture transport, transient eddy, East Asian monsoon

中图分类号:  (Abrupt climate change, stadial-interstadial transitions)

  • 92.30.Bc
92.60.Ry (Climatology, climate change and variability)