气候变化领域集成服务门户(CCPortal): The combined effect of two westerly jet waveguides on heavy haze in the North China Plain in November and December 2015

CCPortal

DOI	10.5194/acp-20-4667-2020
	The combined effect of two westerly jet waveguides on heavy haze in the North China Plain in November and December 2015
	An X.; Sheng L.; Liu Q.; Li C.; Gao Y.; Li J.
发表日期	2020
ISSN	16807316
起始页码	4667
结束页码	4680
卷号	20 期号:8
英文摘要	Severe haze occurred in the North China Plain (NCP) from November to December 2015, with a wide spatial range and long duration. In this paper, the combined effect of the anomalous stationary Rossby waves within two westerly jet waveguides on this haze event in the NCP is investigated based on observational visibility data and NCEP/NCAR reanalysis data. The results show that circulation anomalies in Eurasia caused by the propagation of anomalous stationary Rossby wave energy along two waveguides within the westerly jet originating from the Mediterranean were responsible for haze formation in the NCP. The Rossby waves propagated eastward along the subtropical westerly jet and the polar front jet, causing an anomalous anticyclone over the Sea of Japan and anticyclonic wind shear at 850 hPa over the NCP, which enhanced the anomalous descent in the middle and lower troposphere and subsequently resulted in a stable lower atmosphere. Furthermore, the anomalous stationary Rossby waves propagating along the polar front jet weakened the East Asia trough and Ural ridge and strengthened the anomalous southerly wind at 850 hPa over the coastal areas of eastern China, decelerating the East Asia winter monsoon. The above meteorological conditions modulated haze accumulation in November and December 2015. Meanwhile, continuous rainfall related to ascending motion due to Rossby wave propagation along the waveguide provided by the subtropical westerly jet occurred in a large area of southern China. The associated latent heat release acted as a heat source, intensifying the ascending motion over southern China so that the descending motion over the NCP was strengthened, favoring the maintenance of severe haze. This study elucidates the formation and maintenance mechanism of large-scale haze in the NCP in late fall and boreal winter. © 2020 Copernicus GmbH. All rights reserved.
关键词	anticyclone formation mechanism haze jet flow latent heat flux Rossby wave wave energy wave propagation westerly wind shear China Eurasia North China Plain
语种	英语
来源机构	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/132092
推荐引用方式 GB/T 7714	An X.,Sheng L.,Liu Q.,et al. The combined effect of two westerly jet waveguides on heavy haze in the North China Plain in November and December 2015[J]. Atmospheric Chemistry and Physics,2020,20(8).
APA	An X.,Sheng L.,Liu Q.,Li C.,Gao Y.,&Li J..(2020).The combined effect of two westerly jet waveguides on heavy haze in the North China Plain in November and December 2015.,20(8).
MLA	An X.,et al."The combined effect of two westerly jet waveguides on heavy haze in the North China Plain in November and December 2015".20.8(2020).