气候变化领域集成服务门户(CCPortal): Hemispheric asymmetries in recent changes in the stratospheric circulation

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DOI	10.5194/acp-22-5559-2022
	Hemispheric asymmetries in recent changes in the stratospheric circulation
	Ploeger, Felix; Garny, Hella
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	5559
结束页码	5576
卷号	22 期号:8 页码:18
英文摘要	The expected effect of ozone recovery on the stratospheric Brewer-Dobson circulation (BDC) is a slow-down, strongest in the Southern Hemisphere (SH). In contrast, the BDC has been found to weaken more strongly in the Northern Hemisphere (NH) relative to the SH in recent decades, inducing substantial effects on chemical composition. We investigate hemispheric asymmetries in BDC changes since about 2000 in simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) driven with different reanalyses (ERA5, ERA-Interim, JRA-55, MERRA-2) and contrast those to free-running climate model simulations. We find that age-of-air increases robustly in the NH stratosphere relative to the SH in all reanalyses. Related nitrous oxide changes agree well between reanalysis-driven simulations and satellite measurements, providing observational evidence for the hemispheric asymmetry in BDC changes. We show that the composition changes in reanalyses are caused by structural residual-circulation changes related to an upward shift and strengthening of the deep BDC branch, resulting in longer transit times, and a downward shift and weakening shallow branch in the NH relative to the SH. Although climate model simulations show that ozone recovery will lead to overall reduced circulation and age-of-air trends, the hemispherically asymmetric signal in circulation trends is small compared to internal variability. Therefore, observed circulation trends over the recent past are not in contradiction to expectations from climate models. Furthermore, the hemispheric asymmetry in BDC trends imprints on the composition of the lower stratosphere, and the signal might propagate into the troposphere, potentially affecting composition down to the surface.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000787778000001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273153
作者单位	Helmholtz Association; Research Center Julich; University of Wuppertal; Helmholtz Association; German Aerospace Centre (DLR); University of Munich
推荐引用方式 GB/T 7714	Ploeger, Felix,Garny, Hella. Hemispheric asymmetries in recent changes in the stratospheric circulation[J],2022,22(8):18.
APA	Ploeger, Felix,&Garny, Hella.(2022).Hemispheric asymmetries in recent changes in the stratospheric circulation.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(8),18.
MLA	Ploeger, Felix,et al."Hemispheric asymmetries in recent changes in the stratospheric circulation".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.8(2022):18.