气候变化领域集成服务门户(CCPortal): Near-equatorial tropical cyclone formation in western North Pacific: peak season and controlling parameter

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DOI	10.1007/s00382-018-4291-3
	Near-equatorial tropical cyclone formation in western North Pacific: peak season and controlling parameter
	Li Y.; Li T.; Fu C.; Hsu P.-C.
发表日期	2019
ISSN	0930-7575
起始页码	2765
结束页码	2773
卷号	52 期号:2020-05-06
英文摘要	The near-equatorial (0°–5°N) tropical cyclones (TCs) in the western North Pacific (WNP) exhibit distinctive seasonal variability, with a peak in the boreal winter, as opposite to that in the main TC development region over the WNP. The mechanism behind such a distinctive annual evolution is investigated through the diagnosis of the genesis potential index (GPI). By isolating the effect of various environmental parameters, we found that the increase of the near-equatorial GPI in the boreal winter is primarily attributed by the low-level absolute vorticity. As the season progresses from the boreal summer to winter, the northeasterly trade wind turns anticlockwise near the equator, leading to maximum low-level cyclonic vorticity near 5°N. In addition, the mean flow advection also plays a role in “allowing” more time for perturbations to grow in the near-equatorial zone in DJFMAM than in JASO. The seasonal changes of other environmental conditions, such as relative humidity and sea surface temperature, are not as critical. While the effect of area-averaged vertical wind shear is small due to the opposite signs between western and eastern sectors of the WNP in the boreal winter, a moderate vertical shear over 140–160°E, 2–5°N may favor the development of TC-like disturbances in the region. Our analysis results suggest that dynamic parameters are more important for the formation of near-equatorial TCs. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Genesis potential index; Near-equatorial tropical cyclone; Tropical cyclone genesis
语种	英语
scopus关键词	equatorial dynamics; formation mechanism; seasonal variation; tropical cyclone; vorticity; winter; Pacific Ocean; Pacific Ocean (North)
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146488
作者单位	Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environmental Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing, China; Department of Atmospheric Sciences, School of Ocean and Earth Science and Technology, University of Hawaii, 2525 Correa Rd., Honolulu, HI 96822, United States; College of Atmospheric Science, Nanjing University of Information Science and Technology, Nanjing, China
推荐引用方式 GB/T 7714	Li Y.,Li T.,Fu C.,et al. Near-equatorial tropical cyclone formation in western North Pacific: peak season and controlling parameter[J],2019,52(2020-05-06).
APA	Li Y.,Li T.,Fu C.,&Hsu P.-C..(2019).Near-equatorial tropical cyclone formation in western North Pacific: peak season and controlling parameter.Climate Dynamics,52(2020-05-06).
MLA	Li Y.,et al."Near-equatorial tropical cyclone formation in western North Pacific: peak season and controlling parameter".Climate Dynamics 52.2020-05-06(2019).