Observational constraints on recent increases in the atmospheric CH4 burden
Observational constraints on recent increases in the atmospheric CH4 burden
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DOI：
10.1029/2009gl039780
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发表时间：
2009-09-17
影响因子：
5.2
通讯作者：
Gatti, L. V.
中科院分区：
文献类型：
--
作者：
Dlugokencky, E. J.;Bruhwiler, L.;Gatti, L. V.
从46个偏远地面站点每周收集的空气样本中对大气甲烷的测量表明，在经历了近十年的零增长之后，全球平均大气甲烷在2007年和2008年有所增加。2007年期间，CH4增加了8.3 +/- 0.6 ppb。极地北纬和南半球的CH4摩尔分数平均高于其他纬向平均区域。2008年，全球平均CH4增加4.4 +/- 0.6 ppb；增幅最大的是热带地区，而极北纬地区则没有增加。卫星和原位CO观测表明，生物质燃烧对CH4增加的贡献很小。2007年和2008年观测到的CH4异常最可能的驱动因素是北极的异常高温和热带地区高于平均水平的降水。2008年北极地区甲烷的增长接近于零，这表明我们尚未激活来自永久冻土和甲烷水合物的强烈气候反馈。引用本文：dulgokencky， e.j.等（2009），大气CH4负荷近期增加的观测约束，地球物理。卷。， 36, L18803, doi: 10.1029/2009GL039780。
Measurements of atmospheric CH4 from air samples collected weekly at 46 remote surface sites show that, after a decade of near-zero growth, globally averaged atmospheric methane increased during 2007 and 2008. During 2007, CH4 increased by 8.3 +/- 0.6 ppb. CH4 mole fractions averaged over polar northern latitudes and the Southern Hemisphere increased more than other zonally averaged regions. In 2008, globally averaged CH4 increased by 4.4 +/- 0.6 ppb; the largest increase was in the tropics, while polar northern latitudes did not increase. Satellite and in situ CO observations suggest only a minor contribution to increased CH4 from biomass burning. The most likely drivers of the CH4 anomalies observed during 2007 and 2008 are anomalously high temperatures in the Arctic and greater than average precipitation in the tropics. Near-zero CH4 growth in the Arctic during 2008 suggests we have not yet activated strong climate feedbacks from permafrost and CH4 hydrates. Citation: Dlugokencky, E.J., et al. (2009), Observational constraints on recent increases in the atmospheric CH4 burden, Geophys. Res. Lett., 36, L18803, doi: 10.1029/2009GL039780.