气候变化领域集成服务门户(CCPortal): Influences of hydroxyl radicals (OH) on top-down estimates of the global and regional methane budgets

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DOI	10.5194/acp-20-9525-2020
	Influences of hydroxyl radicals (OH) on top-down estimates of the global and regional methane budgets
	Zhao Y.; Saunois M.; Bousquet P.; Lin X.; Berchet A.; Hegglin M.I.; Canadell J.G.; Jackson R.B.; Dlugokencky E.J.; Langenfelds R.L.; Ramonet M.; Worthy D.; Zheng B.
发表日期	2020
ISSN	1680-7316
起始页码	9525
结束页码	9546
卷号	20 期号:15
英文摘要	The hydroxyl radical (OH), which is the dominant sink of methane (CH 4 ), plays a key role in closing the global methane budget. Current top-down estimates of the global and regional CH 4 budget using 3D models usually apply prescribed OH fields and attribute model-observation mismatches almost exclusively to CH 4 emissions, leaving the uncertainties due to prescribed OH fields less quantified. Here, using a variational Bayesian inversion framework and the 3D chemical transport model LMDz, combined with 10 different OH fields derived from chemistry-climate models (Chemistry-Climate Model Initiative, or CCMI, experiment), we evaluate the influence of OH burden, spatial distribution, and temporal variations on the global and regional CH 4 budget. The global tropospheric mean CH 4 - reaction-weighted [OH] ([OH]GM-CH 4 ) ranges 10.3-16:3× 10 5 molec cm -3 across 10 OH fields during the early 2000s, resulting in inversion-based global CH 4 emissions between 518 and 757 Tg yr -1 . The uncertainties in CH 4 inversions induced by the different OH fields are similar to the CH 4 emission range estimated by previous bottom-up syntheses and larger than the range reported by the top-down studies. The uncertainties in emissions induced by OH are largest over South America, corresponding to large inter-model differences of [OH] in this region. From the early to the late 2000s, the optimized CH 4 emissions increased by 22-6 Tg yr -1 (17-30 Tg yr -1 ), of which 25 % (on average) offsets the 0.7 %(on average) increase in OH burden. If the CCMI models represent the OH trend properly over the 2000s, our results show that a higher increasing trend of CH 4 emissions is needed to match the CH 4 observations compared to the CH 4 emission trend derived using constant OH. This study strengthens the importance of reaching a better representation of OH burden and of OH spatial and temporal distributions to reduce the uncertainties in the global and regional CH 4 budgets. © Author(s) 2020.
语种	英语
scopus关键词	Bayesian analysis; carbon budget; climate modeling; hydroxyl radical; methane; spatiotemporal analysis; trend analysis; uncertainty analysis; South America
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/247588
作者单位	Laboratoire des Sciences du Climat et de l'Environnement, LSCE-IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, 91191, France; Department of Meteorology, University of Reading, Reading, RG6 6LA, United Kingdom; Global Carbon Project, CSIRO Oceans and Atmosphere, Canberra, Australian Capital Territory, 2601, Australia; Earth System Science Department, Woods Institute for the Environment, Precourt Institute for Energy, Stanford University, Stanford, CA 94305, United States; NOAA ESRL, 325 Broadway, Boulder, CO 80305, United States; Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, VIC 3195, Australia; Environment and Climate Change Canada, Toronto, M3H 5T4, Canada; Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109, United States
推荐引用方式 GB/T 7714	Zhao Y.,Saunois M.,Bousquet P.,et al. Influences of hydroxyl radicals (OH) on top-down estimates of the global and regional methane budgets[J],2020,20(15).
APA	Zhao Y..,Saunois M..,Bousquet P..,Lin X..,Berchet A..,...&Zheng B..(2020).Influences of hydroxyl radicals (OH) on top-down estimates of the global and regional methane budgets.ATMOSPHERIC CHEMISTRY AND PHYSICS,20(15).
MLA	Zhao Y.,et al."Influences of hydroxyl radicals (OH) on top-down estimates of the global and regional methane budgets".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.15(2020).