气候变化领域集成服务门户(CCPortal): Atmospheric impacts of chlorinated very short-lived substances over the recent past - Part 1: Stratospheric chlorine budget and the role of transport

CCPortal

DOI	10.5194/acp-22-10657-2022
	Atmospheric impacts of chlorinated very short-lived substances over the recent past - Part 1: Stratospheric chlorine budget and the role of transport
	Bednarz, Ewa M.; Hossaini, Ryan; Chipperfield, Martyn P.; Abraham, N. Luke; Braesicke, Peter
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	10657
结束页码	10676
卷号	22 期号:16 页码:20
英文摘要	Impacts of chlorinated very short-lived substances (Cl-VSLS) on stratospheric chlorine budget over the first two decades of the 21st century are assessed using the Met Office's Unified Model coupled to the United Kingdom Chemistry and Aerosol (UM-UKCA) chemistry-climate model; this constitutes the most upto-date assessment and the first study to simulate Cl-VSLS impacts using a whole atmosphere chemistry-climate model. We examine the Cl-VSLS responses using a small ensemble of free-running simulations and two pairs of integrations where the meteorology was nudged to either ERA5 or ERA-Interim reanalysis. The stratospheric chlorine source gas injection due to Cl-VSLS estimated from the free-running integrations doubled from similar to 40 ppt Cl injected into the stratosphere in 2000 to similar to 80 ppt Cl injected in 2019. Combined with chlorine product gas injection, the integrations showed a total of similar to 130 ppt Cl injected into the stratosphere in 2019 due to Cl-VSLS. The use of the nudged model significantly increased the abundance of Cl-VSLS simulated in the lower stratosphere relative to the free-running model. Averaged over 2010-2018, simulations nudged to ERAI-Interim and ERA5 showed 20 ppt (i.e. a factor of 2) and 10 ppt (i.e. similar to 50 %) more Cl, respectively, in the tropical lower stratosphere at 20 km in the form of Cl-VSLS source gases compared to the free-running case. These differences can be explained by the corresponding differences in the speed of the large-scale circulation. The results illustrate the strong dependence of the simulated stratospheric Cl-VSLS levels on the model dynamical fields. In UM-UKCA, this corresponds to the choice between free-running versus nudged set-up, and to the reanalysis dataset used for nudging. Temporal changes in Cl-VSLS are found to have significantly impacted recent HCl and COCl2 trends in the model. In the tropical lower stratosphere, the inclusion of Cl-VSLS reduced the magnitude of the negative HCl and COCl2 trends (e.g. from similar to -8 %(HC1)/decade and similar to -4 ppt(COCl2)/decade at similar to 20 km to similar to -6 %(HCl)/decade and similar to -2 ppt(COCl2)/decade in the free running simulations) and gave rise to positive tropospheric trends in both tracers. In the tropics, both the free-running and nudged integrations with Cl-VSLS included compared much better to the observed trends from the ACE-FTS satellite record than the analogous simulations without Cl-VSLS. Since observed HCl trends provide information on the evolution of total stratospheric chlorine and, thus, the effectiveness of the Montreal Protocol, our results demonstrate that Cl-VSLS are a confounding factor in the interpretation of such data and should be factored into future analysis. Unlike the nudged model runs, the ensemble mean free-running integrations did not reproduce the hemispheric asymmetry in the observed mid-latitude HCl and COCl2 trends related to short-term dynamical variability. The individual ensemble members also showed a considerable spread of the diagnosed tracer trends, illustrating the role of natural interannual variability in modulating the diagnosed responses and the need for caution when interpreting both model and observed tracer trends derived over a relatively short time period.
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:000842961500001
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/273423
作者单位	Lancaster University; Lancaster University; University of Leeds; University of Leeds; University of Cambridge; University of Cambridge; Helmholtz Association; Karlsruhe Institute of Technology; Cornell University
推荐引用方式 GB/T 7714	Bednarz, Ewa M.,Hossaini, Ryan,Chipperfield, Martyn P.,et al. Atmospheric impacts of chlorinated very short-lived substances over the recent past - Part 1: Stratospheric chlorine budget and the role of transport[J],2022,22(16):20.
APA	Bednarz, Ewa M.,Hossaini, Ryan,Chipperfield, Martyn P.,Abraham, N. Luke,&Braesicke, Peter.(2022).Atmospheric impacts of chlorinated very short-lived substances over the recent past - Part 1: Stratospheric chlorine budget and the role of transport.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(16),20.
MLA	Bednarz, Ewa M.,et al."Atmospheric impacts of chlorinated very short-lived substances over the recent past - Part 1: Stratospheric chlorine budget and the role of transport".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.16(2022):20.