气候变化领域集成服务门户(CCPortal): Gravitational separation of ArN2 and age of air in the lowermost stratosphere in airborne observations and a chemical transport model

CCPortal

DOI	10.5194/acp-20-12391-2020
	Gravitational separation of ArN2 and age of air in the lowermost stratosphere in airborne observations and a chemical transport model
	Birner B.; Chipperfield M.P.; Morgan E.J.; Stephens B.B.; Linz M.; Feng W.; Wilson C.; Bent J.D.; Wofsy S.C.; Severinghaus J.; Keeling R.F.; Birner B.
发表日期	2020
ISSN	1680-7316
起始页码	12391
结束页码	12408
卷号	20 期号:21
英文摘要	Accurate simulation of atmospheric circulation, particularly in the lower stratosphere, is challenging due to unresolved wave-mean flow interactions and limited high-resolution observations for validation. Gravity-induced pressure gradients lead to a small but measurable separation of heavy and light gases by molecular diffusion in the stratosphere. Because the relative abundance of Ar to N2 is exclusively controlled by physical transport, the argon-to-nitrogen ratio (ArN2) provides an additional constraint on circulation and the age of air (AoA), i.e., the time elapsed since entry of an air parcel into the stratosphere. Here we use airborne measurements of N2O and ArN2 from nine campaigns with global coverage spanning 2008-2018 to calculate AoA and to quantify gravitational separation in the lowermost stratosphere. To this end, we develop a new N2O-AoA relationship using a Markov chain Monte Carlo algorithm. We observe that gravitational separation increases systematically with increasing AoA for samples with AoA between 0 and 3 years. These observations are compared to a simulation of the TOMCAT/SLIMCAT 3-D chemical transport model, which has been updated to include gravitational fractionation of gases. We demonstrate that although AoA at old ages is slightly underestimated in the model, the relationship between ArN2 and AoA is robust and agrees with the observations. This highlights the potential of ArN2 to become a new AoA tracer that is subject only to physical transport phenomena and can supplement the suite of available AoA indicators. © 2020 EDP Sciences. All rights reserved.
语种	英语
scopus关键词	airborne sensing; argon; atmospheric chemistry; gravity field; modeling; nitrogen; pressure gradient; stratosphere; tracer
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/247436
作者单位	Scripps Institution of Oceanography, UC San Diego, San diego, CA 92093, United States; School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom; National Centre for Earth Observation, University of Leeds, Leeds, LS2 9JT, United Kingdom; National Center for Atmospheric Research, Boulder, CO 80301, United States; Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, United States; School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States; National Centre for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, United Kingdom; Picarro, Inc., Santa Clara, CA 95054, United States
推荐引用方式 GB/T 7714	Birner B.,Chipperfield M.P.,Morgan E.J.,et al. Gravitational separation of ArN2 and age of air in the lowermost stratosphere in airborne observations and a chemical transport model[J],2020,20(21).
APA	Birner B..,Chipperfield M.P..,Morgan E.J..,Stephens B.B..,Linz M..,...&Birner B..(2020).Gravitational separation of ArN2 and age of air in the lowermost stratosphere in airborne observations and a chemical transport model.ATMOSPHERIC CHEMISTRY AND PHYSICS,20(21).
MLA	Birner B.,et al."Gravitational separation of ArN2 and age of air in the lowermost stratosphere in airborne observations and a chemical transport model".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.21(2020).