气候变化领域集成服务门户(CCPortal): Tropical and extratropical influences on the variability of the southern hemisphere wintertime subtropical jet

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DOI	10.1175/JCLI-D-20-0460.1
	Tropical and extratropical influences on the variability of the southern hemisphere wintertime subtropical jet
	Gillett Z.E.; Hendon H.H.; Arblaster J.M.; Lim E.-P.
发表日期	2021
ISSN	08948755
起始页码	4009
结束页码	4022
卷号	34 期号:10
英文摘要	Interannual variability of the Southern Hemisphere subtropical jet (STJ) is assessed using atmospheric reanalyses during 1979–2018. The focus is on the austral winter season when the STJ is strongest and most distinct from the midlatitude eddy-driven jet (EDJ). Variations in the intensity and latitudinal position of the STJ are diagnosed using an index developed to discriminate between variations associated with the EDJ. STJ intensity and position variations are found to be tied to different mechanisms. An intensification of the STJ is associated with enhanced divergent outflow from diabatic heating over the equatorial Pacific Ocean, primarily resulting from eastern Pacific or canonical El Niño. This intensification is associated with a narrowing of the STJ and an in-place weakening of the EDJ. An equatorward-shifted STJ, however, appears to be eddy driven and is associated with an acceleration and poleward displacement of the EDJ, which projects onto the positive polarity of the southern annular mode. As has previously been reported, El Niño Modoki (or central Pacific El Niño) can act to shift the EDJ poleward during austral winter; thus, a possible pathway for changes in the position of the STJ is via tropically forced changes in the position of the EDJ. In contrast to previous studies, we also highlight a weakening and poleward shift of the STJ in association with an expansion of the Hadley circulation. © 2021 American Meteorological Society.
英文关键词	Angular momentum; Atmospheric circulation; Climate variability; Dynamics; Eddies; ENSO; Wave breaking
语种	英语
scopus关键词	Climate models; Climatology; Diabatic heating; Different mechanisms; Equatorial Pacific Ocean; Hadley circulation; Interannual variability; Positive polarity; Southern Annular Mode; Southern Hemisphere; Tropics
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/178569
作者单位	ARC Centre of Excellence for Climate Extremes, School of Earth, Atmosphere and Environment, Monash University, Melbourne, VIC, Australia; Bureau of Meteorology, Melbourne, VIC, Australia; National Center for Atmospheric Research, Boulder, CO, United States
推荐引用方式 GB/T 7714	Gillett Z.E.,Hendon H.H.,Arblaster J.M.,et al. Tropical and extratropical influences on the variability of the southern hemisphere wintertime subtropical jet[J],2021,34(10).
APA	Gillett Z.E.,Hendon H.H.,Arblaster J.M.,&Lim E.-P..(2021).Tropical and extratropical influences on the variability of the southern hemisphere wintertime subtropical jet.Journal of Climate,34(10).
MLA	Gillett Z.E.,et al."Tropical and extratropical influences on the variability of the southern hemisphere wintertime subtropical jet".Journal of Climate 34.10(2021).