The Australian methane budget: Interpreting surface and train‐borne measurements using a chemistry transport model
The Australian methane budget: Interpreting surface and train‐borne measurements using a chemistry transport model
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DOI：
10.1029/2011jd015964
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发表时间：
2011-10
影响因子：
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通讯作者：
A. Fraser;C. Miller;P. Palmer;N. Deutscher;N. Jones;D. Griffith
中科院分区：
文献类型：
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作者：
A. Fraser;C. Miller;P. Palmer;N. Deutscher;N. Jones;D. Griffith
[1]我们调查了澳大利亚的甲烷预算从2005-2008年使用GEOS-Chem三维化学传输模型，侧重于从不同部门的排放量的相对贡献和长距离传输的影响。为了评估该模型，我们使用现场测量的甲烷，甲烷干空气柱平均值（XCH 4）从地面傅里叶变换光谱仪（FTSs），和列车载表面浓度测量从现场FTS沿着南北大陆样带。我们使用重力恢复和气候实验的重力异常数据来描述湿地排放的时空分布，并将其缩放到先前的排放估计，从而更好地描述了在热带纬度观测到的大气甲烷变化。弗格森角（Cape Ferguson）和格里姆角（Cape Grim）的清洁空气站点受当地排放的影响最小，而位于人口稠密的东南部的卧龙岗（Wollongong）则采样了当地污染最严重的空气质量（占总空气质量的2.5%，而其他站点则<1%）。平均每年，在达尔文的甲烷背景以上的最大的单一来源是远距离传输，主要来自东南亚，占地面浓度变化的25%以上的背景。在弗格森角和格里姆角，反刍动物的排放是高于背景的甲烷的最大来源，分别约占表面浓度的20%和30%。在卧龙岗，煤炭开采排放是高于背景的最大排放源，占表面浓度的60%。火车数据提供了一种有效的方法来观察城市，沙漠和热带景观之间的过渡。
[1] We investigate the Australian methane budget from 2005–2008 using the GEOS-Chem 3D chemistry transport model, focusing on the relative contribution of emissions from different sectors and the influence of long-range transport. To evaluate the model, we use in situ surface measurements of methane, methane dry air column average (XCH4) from ground-based Fourier transform spectrometers (FTSs), and train-borne surface concentration measurements from an in situ FTS along the north–south continental transect. We use gravity anomaly data from Gravity Recovery and Climate Experiment to describe the spatial and temporal distribution of wetland emissions and scale it to a prior emission estimate, which better describes observed atmospheric methane variability at tropical latitudes. The clean air sites of Cape Ferguson and Cape Grim are the least affected by local emissions, while Wollongong, located in the populated southeast with regional coal mining, samples the most locally polluted air masses (2.5% of the total air mass versus <1% at other sites). Averaged annually, the largest single source above background of methane at Darwin is long-range transport, mainly from Southeast Asia, accounting for ∼25% of the change in surface concentration above background. At Cape Ferguson and Cape Grim, emissions from ruminant animals are the largest source of methane above background, at approximately 20% and 30%, respectively, of the surface concentration. At Wollongong, emissions from coal mining are the largest source above background representing 60% of the surface concentration. The train data provide an effective way of observing transitions between urban, desert, and tropical landscapes.