气候变化领域集成服务门户(CCPortal): Role of the surface boundary conditions in boreal spring on the interannual variability of the multistage evolution of the East Asian summer monsoon

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DOI	10.1175/JCLI-D-19-0249.1
	Role of the surface boundary conditions in boreal spring on the interannual variability of the multistage evolution of the East Asian summer monsoon
	Oh H.; Ha K.-J.
发表日期	2020
ISSN	0894-8755
起始页码	1845
结束页码	1861
卷号	33 期号:5
英文摘要	The seasonal movement of the upper-level jet plays a key role in the evolution of the East Asian summer monsoon (EASM). However, it remains unresolved how interannual changes in surface boundary conditions can influence the upper-level flow over East Asia, thereby modulating the onset of the EASM. Here we capture the timing of multistage evolution over East Asia using the upper-level zonal wind in a two-phase linear regression model. In addition, we show the impact of two surface boundary conditions on the timing of the EASM onset related to the strength of the upper-level zonal wind: 1) eastern Eurasian snow cover and 2) western North Pacific (WNP) sea surface temperature (SST) tendency. The eddy heat fluxes induced by the enhanced eastern Eurasian snow cover develop an anomalous anticyclonic circulation to the northwest, which causes anomalous warm southwesterly flow toward the north. These can make a reversal of the meridional temperature gradient, which results in the early monsoon onset via changes in the upper-level jet. The upper-level jet also responds to the SST tendency in April over the WNP via thermal wind balance and the resultant changes in transient eddy-induced heat transport. Our findings suggest potential sources for seasonal predictability in the interannual EASM onset dates. © 2020 American Meteorological Society.
英文关键词	Atmospheric thermodynamics; Boundary conditions; Regression analysis; Snow; Surface waters; Anticyclonic circulation; East Asian summer monsoon; Interannual variability; Linear regression models; Meridional temperature gradient; Sea surface temperature (SST); Surface boundary conditions; Western North Pacific; Oceanography; annual variation; atmospheric dynamics; boundary condition; eddy; heat transfer; jet flow; jet stream; monsoon; sea surface temperature; snow cover; spring (season); summer; zonal wind; Far East; Pacific Ocean; Pacific Ocean (North)
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/171415
作者单位	Center for Climate Physics, Institute for Basic Science, Department of Atmospheric Sciences, Pusan National University, Busan, South Korea
推荐引用方式 GB/T 7714	Oh H.,Ha K.-J.. Role of the surface boundary conditions in boreal spring on the interannual variability of the multistage evolution of the East Asian summer monsoon[J],2020,33(5).
APA	Oh H.,&Ha K.-J..(2020).Role of the surface boundary conditions in boreal spring on the interannual variability of the multistage evolution of the East Asian summer monsoon.Journal of Climate,33(5).
MLA	Oh H.,et al."Role of the surface boundary conditions in boreal spring on the interannual variability of the multistage evolution of the East Asian summer monsoon".Journal of Climate 33.5(2020).