Centre for Atmospheric Science, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
Waste Manag. 2019 Mar 15;87:883-892. doi: 10.1016/j.wasman.2017.12.024. Epub 2018 Jan 9.
This paper describes the development of a new sampling and measurement method to infer methane flux using proxy measurements of CO concentration and wind data recorded by Unmanned Aerial Systems (UAS). The flux method described and trialed here is appropriate to the spatial scale of landfill sites and analogous greenhouse gas emission hotspots, making it an important new method for low-cost and rapid case study quantification of fluxes from currently uncertain (but highly important) greenhouse gas sources. We present a case study using these UAS-based measurements to derive instantaneous methane fluxes from a test landfill site in the north of England using a mass balance model tailored for UAS sampling and co-emitted CO concentration as a methane-emission proxy. Methane flux (and flux uncertainty) during two trials on 27 November 2014 and 5 March 2015, were found to be 0.140 kg s (±61% at 1σ), and 0.050 kg s (±54% at 1σ), respectively. Uncertainty contributing to the flux was dominated by ambient variability in the background (inflow) concentration (>40%) and wind speed (>10%); with instrumental error contributing only ∼1-2%. The approach described represents an important advance concerning the challenging problem of greenhouse gas hotspot flux calculation, and offers transferability to a wide range of analogous environments. This new measurement solution could add to a toolkit of approaches to better validate source-specific greenhouse emissions inventories - an important new requirement of the UNFCCC COP21 (Paris) climate change agreement.
本文描述了一种新的采样和测量方法的发展，该方法通过使用无人机系统 (UAS) 记录的 CO 浓度和风向代理测量值来推断甲烷通量。这里描述和试验的通量方法适用于垃圾填埋场和类似温室气体排放热点的空间尺度，因此是一种从目前不确定（但非常重要）的温室气体源进行低成本、快速案例研究通量量化的重要新方法。我们展示了一个使用这些基于 UAS 的测量值的案例研究，该研究使用针对 UAS 采样定制的质量平衡模型，并将 co-emitted CO 浓度作为甲烷排放的代理，从英格兰北部的一个测试垃圾填埋场中得出瞬时甲烷通量。在 2014 年 11 月 27 日和 2015 年 3 月 5 日的两次试验中，发现甲烷通量（和通量不确定性）分别为 0.140kg/s（±61%，1σ）和 0.050kg/s（±54%，1σ）。对通量有贡献的不确定性主要由背景（流入）浓度的环境变异性（>40%）和风速（>10%）引起；仪器误差仅贡献了约 1-2%。所描述的方法代表了温室气体热点通量计算这一具有挑战性问题的重要进展，并具有广泛类似环境的可转移性。这种新的测量解决方案可以补充一系列方法，以更好地验证特定源的温室气体排放清单-联合国气候变化框架公约 COP21（巴黎）气候变化协议的一个新的重要要求。
