Scopus记录号: 2-s2.0-85062662815
论文题名: Interannual relationship between intensity of rainfall intraseasonal oscillation and summer-mean rainfall over Yangtze River Basin in eastern China
作者: Qi Y. ; Li T. ; Zhang R. ; Chen Y.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2019
语种: 英语
英文关键词: Intraseasonal oscillation
; Summer rainfall
; Yangtze River Basin
英文摘要: The analysis of observational rainfall shows that the intensity of rainfall intraseasonal oscillation (ISO) and the summer-mean rainfall over the middle-lower reaches of the Yangtze River Basin (YRB) exhibit a significant positive correlation during 1979–2007. A stronger (weaker) ISO variability is often associated with wet (dry) summer in the YRB. The composite ISOs in both the wet and dry summers are further analyzed. In the wet summers, the rainfall ISO in YRB is primarily associated with the northward propagation of a low-level cyclone-anticyclone pair from the tropics. Cyclonic vorticity and associated boundary layer convergence strengthen the rainfall in situ. In contrast, the rainfall ISO in YRB in the dry summers is primarily associated with the westward propagation of an anomalous anticyclone. Southerly flow to the west of the anomalous anticyclone enhances rainfall in YRB through anomalous moisture advection. In addition to the difference in ISO propagation, the background mean state also shows a marked difference. The diagnosis of water vapor flux budget shows that the convergence and advection of seasonal mean moisture play a critical role in maintenance of the intraseasonal rainfall in the YRB. A greater mean ascending motion and associated higher mean moisture in YRB in the wet summers favor greater intraseasonal rainfall variability in situ. The mean state difference is responsible for distinctive vertical structures of boundary layer vertical velocity. A possible feedback of the ISO to the summer-mean rainfall over the YRB is also discussed. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature. 资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/122511
Appears in Collections: 气候变化事实与影响
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作者单位: State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China; Department of Atmospheric Sciences, International Pacific Research Center, University of Hawaii at Manoa, Honolulu, United States; Department of Atmospheric and Oceanic Sciences & Institute of Atmospheric Sciences, Fudan University, Shanghai, China
Recommended Citation:
Qi Y.,Li T.,Zhang R.,et al. Interannual relationship between intensity of rainfall intraseasonal oscillation and summer-mean rainfall over Yangtze River Basin in eastern China[J]. Climate Dynamics,2019-01-01