气候变化领域集成服务门户(CCPortal): Towards reconstructing the Arctic atmospheric methane history over the 20th century: measurement and modelling results for the North Greenland Ice Core Project firn

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DOI	10.5194/acp-22-6899-2022
	Towards reconstructing the Arctic atmospheric methane history over the 20th century: measurement and modelling results for the North Greenland Ice Core Project firn
	Umezawa, Taku; Sugawara, Satoshi; Kawamura, Kenji; Oyabu, Ikumi; Andrews, Stephen J.; Saito, Takuya; Aoki, Shuji; Nakazawa, Takakiyo
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	6899
结束页码	6917
卷号	22 期号:10 页码:19
英文摘要	Systematic measurements of atmospheric methane (CH4) mole fractions at the northern high latitudes only began in the early 1980s. Although CH4 measurements from Greenland ice cores consistently covered the period before similar to 1900, no reliable observational record is available for the intermediate period. We newly report a data set of trace gases from the air trapped in firn (an intermediate stage between snow and glacial ice formation) collected at the NGRIP (North Greenland Ice Core Project) site in 2001. We also use a set of published firn air data at the NEEM (North Greenland Eemian ice Drilling) site. The two Arctic firn air data sets are analysed with a firn air transport model, which translates historical variations to depth profiles of trace gases in firn. We examine a variety of possible firn diffusivity profiles, using a suite of measured trace gases, and reconstruct the CH4 mole fraction by an iterative dating method. Although the reconstructions of the Arctic CH4 mole fraction before the mid-1970s still has large uncertainties (> 30 ppb - parts per billion), we find a relatively narrow range of atmospheric CH4 history that is consistent with both depth profiles of NGRIP and NEEM. The atmospheric CH4 history inferred by this study is more consistent with the atmospheric CH4 scenario prepared for the NEEM firn modelling than that for the CMIP6 (Climate Model Intercomparison Project Phase 6) experiments. Our study shows that the atmospheric CH4 scenario used for the NEEM firn modelling is considered to be the current best choice for the Arctic CH4 history, but it should not be used to tune firn air transport models until being verified by further measurements from sources such as the Arctic ice cores. Given the current difficulty in reconstructing the CH4 history with low uncertainty from the firn air data sets from Greenland, future sampling and measurements of ice cores at a high-accumulation site may be the only way to accurately reconstruct the atmospheric CH4 trend over the 20th century.
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:000802160600001
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/273368
作者单位	National Institute for Environmental Studies - Japan; Miyagi University Education; Research Organization of Information & Systems (ROIS); National Institute of Polar Research (NIPR) - Japan; Graduate University for Advanced Studies - Japan; Japan Agency for Marine-Earth Science & Technology (JAMSTEC); University of York - UK; Tohoku University; National Institute for Environmental Studies - Japan
推荐引用方式 GB/T 7714	Umezawa, Taku,Sugawara, Satoshi,Kawamura, Kenji,et al. Towards reconstructing the Arctic atmospheric methane history over the 20th century: measurement and modelling results for the North Greenland Ice Core Project firn[J],2022,22(10):19.
APA	Umezawa, Taku.,Sugawara, Satoshi.,Kawamura, Kenji.,Oyabu, Ikumi.,Andrews, Stephen J..,...&Nakazawa, Takakiyo.(2022).Towards reconstructing the Arctic atmospheric methane history over the 20th century: measurement and modelling results for the North Greenland Ice Core Project firn.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(10),19.
MLA	Umezawa, Taku,et al."Towards reconstructing the Arctic atmospheric methane history over the 20th century: measurement and modelling results for the North Greenland Ice Core Project firn".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.10(2022):19.