Methane at the edge: jointly developing state-of-the-art high-precision methods to understand atmospheric methane emissions.

甲烷排放是一个全球性问题，但大部分研究集中在主要研究小组所在的欧洲、北美和澳大拉西亚。许多领域都没有得到充分的研究。需要在主要研究中心之间加强实验室测量和实地技术的相互作用和相互校准，以便提供这些区域的可比数据。此外，中国的温室气体排放量在过去十年中迅速上升，但甲烷的来源尚未得到很好的量化。我们已确定三个国际合作范畴，旨在改善互动，并将新知识和技术应用于香港的新测量地点。甲烷是第二重要的人为温室气体，其产生的来源多种多样，从天然气和煤炭开采和加工过程中的气体泄漏，到奶牛和农业来源，再到自然湿地和火灾。甲烷排放中的碳同位素比例因来源而异，从燃烧源和许多天然气田泄漏的典型“重”（富含13C）到北部湿地排放的典型“轻”。这种同位素特征提供了一种方法，可以识别到达偏远地区的空气中甲烷的来源，以及来自人口稠密的城市中心的混合羽流。这个提议有三个相互关联的泵启动组件，以帮助我们测量甲烷排放并更好地了解它们。第一部分是将英国和欧洲进行的同位素测量与美国NOAA/INSTAAR联盟进行的测量更紧密地联系起来，后者在这项工作中处于世界领先地位。特别是通过相互比较气体标准，我们可以得到一个共同的校准，从而产生一个背景站的关联数据集。其次，这项工作将把英国的工作与澳大利亚CSIRO小组联系起来，他们是使用移动车载系统进行现场测量的主要专家之一。这对于研究气井（包括水力压裂）、煤矿、垃圾填埋场和牛棚等资源的技能转移尤其有用。最后，作为一项概念验证研究，我们将与香港大学合作，对新方法进行实地测试。我们打算在该岛最南端的东南角建立一个测量站，并对从上海开始沿中国沿海以及之前从中国最西北部（NOAA/INSTAAR有长期测量时间序列）传播的冬季东北风进行反向轨迹采样。在夏季，反向流动发生。通过这种方式，我们可以研究是否有可能量化中国的甲烷排放量，并找到源组合在冬季变化时的同位素特征。

Methane emissions are a global problem, but much of the research focusses on Europe, North America and Australasia where the main research groups are based. Many areas are poorly studied. More interaction and intercalibration of laboratory measurement and field techniques between the main research centres is required to provide comparable data across these regions. Additionally emissions of greenhouse gases from China have risen rapidly over the past decade, but the sources of methane are not well quantified. Three areas of international collaboration have been identified that aim to improve interaction and apply new knowledge and techniques to a new measurement site in Hong Kong.Methane, which is the second-most important anthropogenic greenhouse gas, is produced by a wide variety of sources, ranging from gas leaks from natural gas and coal extraction and processing, to cows and agricultural sources, to natural wetlands and fires. The carbon isotopic ratio in methane emissions varies greatly depending on the source, from typically 'heavy' (richer in 13C) in combustion sources and many natural gasfield leaks, to typically 'light' in northern wetland emissions. This isotopic signature provides a method of idetifying methane sources in air arriving at remote sites and in mixed plumes from densely-populated urban centres.This proposal has three linked pump-priming components to help us measure methane emissions and understand them better. The first part is to link the isotopic measurements made in the UK and Europe much more closely with the measurements made by the US NOAA/INSTAAR consortium, who are world leaders in this work. In particular by intercomparing gas standards we can come to a common calibration, and thus produce a linked data set of background stations. Secondly, the work will link UK work with the Australian CSIRO group who are among the leading experts at field measurement using mobile vehicle-mounted systems. This will be particularly useful in skills transfer in studying sources such as gas wells (including fracking), coal mines, landfills and cow barns. Finally, as a proof of concept study, we will collaborate with the University of Hong Kong on a field test of the new methodologies. We intend to set up a measurement station on the extreme SE tip of the island, and sample winter north easterly air with back-trajectories, that has travelled along the Chinese coast from Shanghai, and before that from extreme NW China, where NOAA/INSTAAR have a long-running measurement time series. In summer the reverse flow occurs. In this way we can investigate if it is possible to quantify Chinese emissions of methane and find the isotopic signature of the source mix as it changes over the winter season.