气候变化领域集成服务门户(CCPortal): Origins of east asian summer monsoon seasonality

CCPortal

DOI	10.1175/JCLI-D-19-0888.1
	Origins of east asian summer monsoon seasonality
	Chiang J.C.H.; Kong W.; Wu C.H.; Battisti D.S.
发表日期	2020
ISSN	0894-8755
起始页码	7945
结束页码	7965
卷号	33 期号:18
英文摘要	The East Asian summer monsoon is unique among summer monsoon systems in its complex seasonality, exhibiting distinct intraseasonal stages. Previous studies have alluded to the downstream influence of the westerlies flowing around the Tibetan Plateau as key to its existence. We explore this hypothesis using an atmospheric general circulation model that simulates the intraseasonal stages with fidelity. Without a Tibetan Plateau, East Asia exhibits only one primary convective stage typical of other monsoons. As the plateau is introduced, the distinct rainfall stages—spring, pre-mei-yu, mei-yu, and midsummer—emerge, and rainfall becomes more intense overall. This emergence coincides with a pronounced modulation of the westerlies around the plateau and extratropical northerlies penetrating northeastern China. The northerlies meridionally constrain the moist southerly flow originating from the tropics, leading to a band of lower-tropospheric convergence and humidity front that produces the rainband. The northward migration of the westerlies away from the northern edge of the plateau leads to a weakening of the extratropical northerlies, which, coupled with stronger monsoonal southerlies, leads to the northward migration of the rainband. When the peak westerlies migrate north of the plateau during the midsummer stage, the extratropical northerlies disappear, leaving only the monsoon low-level circulation that penetrates northeastern China; the rainband disappears, leaving isolated convective rainfall over northeastern China. In short, East Asian rainfall seasonality results from the interaction of two seasonally evolving circulations—the monsoonal southerlies that strengthen and extend northward, and the midlatitude northerlies that weaken and eventually disappear—as summer progresses. © 2020 American Meteorological Society.
英文关键词	Atmospheric humidity; Rain; Atmospheric general circulation models; East Asian summer monsoon; Extratropical; Intra-seasonal; Midlatitudes; Seasonality; Summer monsoon; Tibetan Plateau; Atmospheric thermodynamics; atmospheric general circulation model; complexity; extratropical environment; monsoon; regional climate; seasonality; summer; troposphere; westerly; China; Far East; Qinghai-Xizang Plateau; Citrus maxima
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171118
作者单位	Department of Geography and Berkeley Atmospheric Sciences Center, University of California, Berkeley, CA, United States; Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan; Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States
推荐引用方式 GB/T 7714	Chiang J.C.H.,Kong W.,Wu C.H.,et al. Origins of east asian summer monsoon seasonality[J],2020,33(18).
APA	Chiang J.C.H.,Kong W.,Wu C.H.,&Battisti D.S..(2020).Origins of east asian summer monsoon seasonality.Journal of Climate,33(18).
MLA	Chiang J.C.H.,et al."Origins of east asian summer monsoon seasonality".Journal of Climate 33.18(2020).