气候变化领域集成服务门户(CCPortal): On the Contributions of Incipient Vortex Circulation and Environmental Moisture to Tropical Cyclone Expansion

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DOI	10.1029/2020JD033324
	On the Contributions of Incipient Vortex Circulation and Environmental Moisture to Tropical Cyclone Expansion
	Martinez J.; Nam C.C.; Bell M.M.
发表日期	2020
ISSN	2169897X
卷号	125 期号:21
英文摘要	This study investigates the contributions of incipient vortex circulation and midlevel moisture to tropical cyclone (TC) expansion within an idealized numerical modeling framework. We find that the incipient vortex circulation places the primary constraint on TC expansion. Increasing the midlevel moisture further promotes expansion but mostly expedites the intensification process. The expansion rate for initially large vortices exhibits a stronger response to increasing the midlevel moisture compared to initially small vortices. Previous studies have noted a proclivity for relatively small TCs to stay small and relatively large TCs to stay large; that is, TCs possess a sort of “memory” with respect to their incipient circulation. We reproduce this finding with an independent modeling framework and further demonstrate that an initially large vortex can expand more quickly than its relatively smaller counterpart; therefore, with all other factors contributing to expansion held constant, the contrast in size between the two vortices will increase with time. Varying the incipient vortex circulation is associated with subsequent variations in the amount and scale of outer-core convection. As the incipient vortex circulation decreases, outer-core convection is relatively scarce and characterized by small-scale, isolated convective elements. On the contrary, as the incipient vortex circulation increases, outer-core convection abounds and is characterized by relatively large rainbands and mesoscale convective systems. A combined increase in the amount and scale of outer-core convection permits an initially large vortex to converge a substantially greater amount of absolute angular momentum compared to its relatively smaller counterpart, resulting in distinct expansion rates. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	convection; expansion; hurricanes/typhoons; moisture; size; tropical cyclones
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185668
作者单位	Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States
推荐引用方式 GB/T 7714	Martinez J.,Nam C.C.,Bell M.M.. On the Contributions of Incipient Vortex Circulation and Environmental Moisture to Tropical Cyclone Expansion[J],2020,125(21).
APA	Martinez J.,Nam C.C.,&Bell M.M..(2020).On the Contributions of Incipient Vortex Circulation and Environmental Moisture to Tropical Cyclone Expansion.Journal of Geophysical Research: Atmospheres,125(21).
MLA	Martinez J.,et al."On the Contributions of Incipient Vortex Circulation and Environmental Moisture to Tropical Cyclone Expansion".Journal of Geophysical Research: Atmospheres 125.21(2020).