Country-scale greenhouse gases budgets using shipborne measurements: a case study for the United Kingdom and Ireland
Country-scale greenhouse gases budgets using shipborne measurements: a case study for the United Kingdom and Ireland
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DOI：
10.5194/acp-2018-948
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发表时间：
2018-10
影响因子：
6.3
通讯作者：
C. Helfter;N. Mullinger;M. Vieno;S. O'Doherty;M. Ramonet;P. Palmer;E. Nemitz
中科院分区：
文献类型：
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作者：
C. Helfter;N. Mullinger;M. Vieno;S. O'Doherty;M. Ramonet;P. Palmer;E. Nemitz
摘要。我们提出了一种质量平衡方法，通过在英国东海岸的渡轮上进行的浓度测量，估算英国（不包括苏格兰）和爱尔兰共和国的二氧化碳（CO2）和甲烷（CH4）的季节性和年度预算，为期3年（2015-2017年）。我们估计CH4的年排放量为2.55±0.43 Tg，这与各国向《联合国气候变化框架公约》报告的合计2.29 Tg一致。二氧化碳净收支（即包括所有人为和生物源的二氧化碳源和汇）估计为881.0±137.5 Tg，生物源的净贡献为458.7 Tg（取净排放量估计值与仅考虑人为排放的清查值之间的差额）。这两种气体的最大排放发生在较宽的纬度带（52.5°N - 54°N），与人口稠密地区相吻合。这两种气体的排放都是季节性的（冬季最大，夏季最小），与天然气的使用密切相关，在较小程度上也与平均气温反相关。在52.8°N - 54°N的中部地区，甲烷排放量与气温在季节时间尺度上呈显著的负相关，废弃物处理设施密度较高。由于表层土壤CH4氧化电位的变化，垃圾填埋场的甲烷排放有时会随着气温的降低而增加，我们推测废物部门对该中部地区的CH4收支有重要贡献。本研究对使用替代产品（如飞机测量的质量平衡预算、逆模型、清单）估算的排放预算进行了独立验证，并提供了调查这些排放的季节性的机会，而这通常是不可能的。
Abstract. We present a mass balance approach to estimate the seasonal and annual budgets of carbon dioxide (CO2) and methane (CH4) of the United Kingdom (excluding Scotland) and the Republic of Ireland from concentration measurements taken on a ferry along the east coast of the United Kingdom over a 3-year period (2015–2017). We estimate the annual emissions of CH4 to be 2.55 ± 0.43 Tg, which is consistent with the combined 2.29 Tg reported to the United Nations Framework Convention on Climate Change by the individual countries. The net CO2 budget (i.e. including all anthropogenic and biogenic sources and sinks of CO2) is estimated at 881.0 ± 137.5 Tg, with a net biogenic contribution of 458.7 Tg (taken as the difference between the estimated net emissions and the inventory value which accounts for anthropogenic emissions only). The largest emissions for both gases were observed in a broad latitudinal band (52.5° N–54° N), which coincides with densely populated areas. The emissions of both gases were seasonal (maxima in winter and minima in summer), strongly correlated to natural gas usage and, to a lesser extent, also anti-correlated to mean air temperature. Methane emissions exhibited a statistically significant anti-correlation with air temperature at the seasonal time scale in the central region spanning 52.8° N–54° N, which hosts a relatively high density of waste treatment facilities. Methane emissions from landfills have been shown to sometimes increase with decreasing air temperature due to changes in the CH4-oxidizing potential of the top soil, and we speculate that the waste sector contributes significantly to the CH4 budget of this central region. This study brings independent verification of the emission budgets estimated using alternative products (e.g. mass balance budgets by aircraft measurements, inverse modelling, inventorying) and offers an opportunity to investigate the seasonality of these emissions which is usually not possible.