Advances in Atmospheric Sciences

, Volume 29, Issue 1, pp 157–168

Interdecadal modulation of the influence of La Niña events on mei-yu rainfall over the Yangtze River valley

Authors

  • Xin Wang王 鑫
    • Guy Carpenter Asia-Pacific Climate Impact Centre, School of Energy and EnvironmentCity University of Hong Kong
  • Dongxiao Wang王东晓
    • Key Laboratory of Tropical Marine Environmental Dynamics, South China Sea Institute of OceanologyChinese Academy of Sciences
    • Guy Carpenter Asia-Pacific Climate Impact Centre, School of Energy and EnvironmentCity University of Hong Kong
  • Chongyin Li李崇银
    • State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric PhysicsChinese Academy of Sciences
Article

DOI: 10.1007/s00376-011-1021-8

Cite this article as:
Wang, X., Wang, D., Zhou, W. et al. Adv. Atmos. Sci. (2012) 29: 157. doi:10.1007/s00376-011-1021-8

Abstract

The aim of this study was to investigate changes in the relationship between mei-yu rainfall over East China and La Niña events in the late 1970s, a period concurrent with the Pacific climate shift, using meiyu rainfall data and the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis. This relationship was modulated by the climate shift: Before the 1977/1978 climate shift and after the 1992/1993 climate shift, mei-yu rainfall levels were above normal in most La Niña years, whereas during the period 1979–1991, mei-yu rainfall was usually below normal levels in La Niña years.

Both composite analyses and results from an atmospheric general circulation model show remarkable detail in terms of La Niña’s impacts on mei-yu rainfall in the late 1970s due to the change in the mean climatic state over the tropical Pacific. After the late 1970s, the tropical Pacific SSTs were warmer, and the mean state of low-level anticyclone circulation over the western North Pacific (WNP) weakened. Superimposed on La Niña-related cyclonic anomaly over the WNP, anticyclonic circulation weakened. Prior to the late 1970s, the mean state of low-level anticyclone circulation over the WNP was stronger and was less affected by La Niña-related anomalous cyclones. Anticyclone circulation may have brought moisture to the Yangtze River valley, leading to above-normal rainfall.

Key words

mei-yu decadal modulation La Niña

Copyright information

© Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer-Verlag Berlin Heidelberg 2012