Climate Change Research ›› 2019, Vol. 15 ›› Issue (1): 12-22.doi: 10.12006/j.issn.1673-1719.2018.082

• Changes in Climate System • Previous Articles     Next Articles

Decadal variation of rainfall in May over Northeast China since the early 21st century and possible causes

Heng GUO,Zi-Niu XIAO   

  1. State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
  • Received:2018-05-28 Revised:2018-08-25 Online:2019-01-30 Published:2019-01-30
  • Contact: Zi-Niu XIAO

Abstract:

Based on monthly gauged rainfall data in Northeast China and the global atmospheric and oceanic reanalysis dataset for 1961-2015, the decadal changes of rainfall in May over Northeast China (NEC) as well as its relationship with atmospheric circulation and sea surface temperature were investigated using statistical and diagnostic methods. Different from that in late-summer, the rainfall in May over NEC depicted negative anomalies during 1984-1993 and positive anomalies during the early 21st century. The decadal changes of rainfall in May over NEC is mainly attributed to the decadal variation of Northern East Asian Low (NEAL) in May. During the early 21st century, the NEAL was much stronger than its climatology, resulting in surplus rainfall over NEC. Nevertheless, the NEAL was weakened into a shallow trough during 1984-1993, leading to deficient rainfall over NEC. A wave train in the geopotential height field over the Eurasia causes significant vertical motion over the Northern East Asia, which contributes to the above variation of the NEAL. The sea surface temperature anomalies over the tropical North Atlantic in May is the possible external forcing generating the above wave train, which gives rise to the corresponding decadal changes of rainfall over NEC.

Key words: Northeast China, Rainfall in May, Decadal changes, Northern East Asian Low (NEAL), North Atlantic sea surface temperature

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