气候变化领域集成服务门户(CCPortal): Limitations of the radon tracer method (RTM) to estimate regional greenhouse gas (GHG) emissions

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DOI	10.5194/acp-21-17907-2021
	Limitations of the radon tracer method (RTM) to estimate regional greenhouse gas (GHG) emissions - A case study for methane in Heidelberg
	Levin I.; Karstens U.; Hammer S.; Dellacoletta J.; Maier F.; Gachkivskyi M.
发表日期	2021
ISSN	1680-7316
起始页码	17907
结束页码	17926
卷号	21 期号:23
英文摘要	Correlations of nighttime atmospheric methane (CH4) and 222radon (222Rn) observations in Heidelberg, Germany, were evaluated with the radon tracer method (RTM) to estimate the trend of annual nocturnal CH4 emissions from 1996-2020 in the footprint of the station. After an initial 30ĝ€¯% decrease in emissions from 1996 to 2004, there was no further systematic trend but small inter-annual variations were observed thereafter. This is in accordance with the trend of total emissions until 2010 reported by the EDGARv6.0 inventory for the surroundings of Heidelberg and provides a fully independent top-down verification of the bottom-up inventory changes. We show that the reliability of total nocturnal CH4 emission estimates with the RTM critically depends on the accuracy and representativeness of the 222Rn exhalation rates estimated from soils in the footprint of the site. Simply using 222Rn fluxes as estimated by Karstens et al. (2015) could lead to biases in the estimated greenhouse gas (GHG) fluxes as large as a factor of 2. RTM-based GHG flux estimates also depend on the parameters chosen for the nighttime correlations of CH4 and 222Rn, such as the nighttime period for regressions and the R2 cut-off value for the goodness of the fit. Quantitative comparison of total RTM-based top-down flux estimates with bottom-up emission inventories requires representative high-resolution footprint modelling, particularly in polluted areas where CH4 emissions show large heterogeneity. Even then, RTM-based estimates are likely biased low if point sources play a significant role in the station footprint as their emissions may not be fully captured by the RTM method, for example, if stack emissions are injected above the top of the nocturnal inversion layer or if point-source emissions from the surface are not well mixed into the footprint of the measurement site. Long-term representative 222Rn flux observations in the footprint of a station are indispensable in order to apply the RTM method for reliable quantitative flux estimations of GHG emissions from atmospheric observations. © 2021 The Author(s).
语种	英语
scopus关键词	annual variation; emission; greenhouse gas; methane; radon isotope; tracer; Baden-Wurttemberg; Germany; Heidelberg
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/246384
作者单位	Institut für Umweltphysik, Heidelberg University, INF 229, Heidelberg, 69120, Germany; ICOS ERIC Carbon Portal, Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, Lund, 22362, Sweden; ICOS Central Radiocarbon Laboratory, Heidelberg University, Berliner Straße 53, Heidelberg, 69120, Germany
推荐引用方式 GB/T 7714	Levin I.,Karstens U.,Hammer S.,et al. Limitations of the radon tracer method (RTM) to estimate regional greenhouse gas (GHG) emissions - A case study for methane in Heidelberg[J],2021,21(23).
APA	Levin I.,Karstens U.,Hammer S.,Dellacoletta J.,Maier F.,&Gachkivskyi M..(2021).Limitations of the radon tracer method (RTM) to estimate regional greenhouse gas (GHG) emissions - A case study for methane in Heidelberg.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(23).
MLA	Levin I.,et al."Limitations of the radon tracer method (RTM) to estimate regional greenhouse gas (GHG) emissions - A case study for methane in Heidelberg".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.23(2021).