Variability in the East Asian Monsoon: a review

Meteorological applications

article

Kyung-Ja Ha¹  Ki-Young Heo²  Sun-Seon Lee¹  Kyung-Sook Yun¹  Jong-Ghap Jhun³ 

[1] Division of Earth Environmental System, Department of Atmospheric Sciences, Pusan National University;Climate Change & Coastal Disaster Research Department, Korea Ocean Research and Development Institute;School of Earth and Environmental Sciences/Research Institute of Oceanography, Seoul National University

关键词: multiscale variability;    East Asian summer monsoon;    East Asian winter monsoon;    heavy rainfall;    NPISO–ENSO relationship;   

DOI  :  10.1002/met.1320

学科分类：社会科学、人文和艺术（综合）

来源: Wiley

【 摘 要 】

This study presents reviews of recent research on the structure and the multiscale variability in the East Asian monsoon. The boreal summer and winter seasons in the East Asian monsoon region exhibit significant intraseasonal, interannual and interdecadal variabilities. The interannual intensity of the East Asian summer monsoon (EASM) is mainly associated with the position of the centre of the Bonin High, which may be distinguished from the North Pacific anticyclone. The frequencies of heavy rainfall events and associated rainfall amounts increase, and extreme heavy rainfall is higher in August than in July, due to changes that occurred in the August rainfall-El Niño-Southern Oscillation (ENSO) relationship around the mid-1970s. This intraseasonal variability in EASM plays a more important role in the explanations of the interannual variability and climate change than does the annual mean. The interannual variability in the East Asian winter monsoon (EAWM) depends on the behaviour of the Siberian High (SH), Aleutian Low and the subtropical westerly jet stream. An EAWM index that takes into account the meridional shear of a 300 hPa zonal wind is a good indicator to represent the intensity of the EAWM. The Arctic Oscillation has a close relationship with the EAWM intensity on the decadal time scale. Distinct sub-seasonal variability is characterized with northward propagation and is observed in the interdecadal change in the monsoonal intraseasonal oscillation (ISO)-ENSO relationship. The preceding winter ENSO influenced the early summer northward propagating ISO (NPISO) activity before the late 1970s, whereas a strong NPISO–ENSO relationship appeared during the later summer after the late 1970s. The NPISO–ENSO relationship is robust owing to a tropical atmospheric bridge process involving the Walker Circulation and Rossby Wave propagation.

【 授权许可】

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