The Potential Impacts of Warmer-Continent-Related Lower-Layer Equatorial Westerly Wind on Tropical Cyclone Initiation

CORC > 南海海洋研究所 > 中国科学院南海海洋研究所 > 热带海洋环境国家重点实验室(LTO)

	The Potential Impacts of Warmer-Continent-Related Lower-Layer Equatorial Westerly Wind on Tropical Cyclone Initiation
	Yuan, ZJ ; Qian, YK ; Qi, JD ; Wu, JJ
刊名	ADVANCES IN ATMOSPHERIC SCIENCES
	2012
卷号	29 期号:2 页码:333-343
关键词	tropical cyclone human activities climate change global warming
ISSN号	0256-1530
通讯作者	qianyk@mail2.sysu.edu.cn
中文摘要	Global climate models predict that the increasing Amazonian-deforestation rates cause rising temperatures (increases of 1.8 degrees C to 8 degrees C under different conditions) and Amazonian drying over the 21st century. Observations in the 20th century also show that over the warmer continent and the nearby western South Atlantic Ocean, the lower-layer equatorial westerly wind (LLEWW) strengthens with the initiation of tropical cyclones (TCs). The warmer-continent-related LLEWW can result from the Coriolis-force-induced deflection of the cross-equatorial flow (similar to the well-known heat-island effect on sea breeze) driven by the enhanced land-sea contrast between the warmer urbanized continents and relatively cold oceans. This study focuses on the processes relating the warmer-continent-related LLEWW to the TC initiation and demonstrates that the LLEWW embedded in trade easterlies can directly initiate TCs by creating cyclonic wind shears and forming the intertropical convergence zone. In addition to this direct effect, the LLEWW combined with the rotating Earth can boost additional updraft vapor over the high sea-surface temperature region (factor 1), facilitating a surface-to-midtroposphere moist layer (factor 2) and convective instability (factor 3) followed by diabatic processes. According to previous studies, the diabatic heating in a finite equatorial region also activates TCs (factor 4) on each side of the Equator with weak vertical shear (factor 5). Factors 1-5 are favorable conditions for the initiation of severe TCs. Statistical analyses show that the earliest signal of sustained LLEWW not only leads the earliest signal of sustained tropical depression by >3 days but also explains a higher percentage of total variance.
学科主题	Meteorology & Atmospheric Sciences
语种	英语
WOS记录号	WOS:000300530700011
公开日期	2013-08-28
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/10203]
专题	南海海洋研究所_热带海洋环境国家重点实验室(LTO)
推荐引用方式 GB/T 7714	Yuan, ZJ,Qian, YK,Qi, JD,et al. The Potential Impacts of Warmer-Continent-Related Lower-Layer Equatorial Westerly Wind on Tropical Cyclone Initiation[J]. ADVANCES IN ATMOSPHERIC SCIENCES,2012,29(2):333-343.
APA	Yuan, ZJ,Qian, YK,Qi, JD,&Wu, JJ.(2012).The Potential Impacts of Warmer-Continent-Related Lower-Layer Equatorial Westerly Wind on Tropical Cyclone Initiation.ADVANCES IN ATMOSPHERIC SCIENCES,29(2),333-343.
MLA	Yuan, ZJ,et al."The Potential Impacts of Warmer-Continent-Related Lower-Layer Equatorial Westerly Wind on Tropical Cyclone Initiation".ADVANCES IN ATMOSPHERIC SCIENCES 29.2(2012):333-343.