The Global Methane Budget

全球甲烷预算

基本信息

批准号：
NE/N016122/1
负责人：
John Adrian Pyle
金额：
$ 34.53万
依托单位：
University of Cambridge
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FN016122%2F1
关键词：
Global Methane Budget

项目摘要

Atmospheric methane has been increasing in concentration sharply since 2007, for reasons that are not fully understood, with ever-increasing uncertainty in how it should be treated in future climate projects. Overall, the increase since 2007 is comparable to the largest growth events in the Holocene. The largest rises in concentration have been seen in the tropics and southern hemisphere, with the sharpest year-on-year increase thus far occurring in 2014. Strong growth continues in 2015. Carbon isotopic evidence suggests that the increase is due to sources that are predominantly biogenic, with changes in anthropogenic sources (for example natural gas leakage, fracking and so on) playing a more minor role. This, taken with the tropical locus on growth, suggests that the increase has primarily been driven by meteorological change. However, the global methane budget is not well described. "Bottom-up" estimates, made by aggregating inventories of emissions (e.g. from gas leaks, fires, landfills, cows, wetlands, etc) balanced with known loss processes, are significantly different from '"top-down" budgets assessed by direct measurement of the atmosphere. Why this discrepancy occurs is not known.The project has four components, each with a number of work packages.1. Better Observations are needed, to support regional and global atmospheric modelling to derive estimates of emissions. The project will support a UK observation network for methane and its isotopes. Continuous stations will be at Kjolnes (Norway), Weybourne, Jersey, NERC ship RRS JC Ross, Cape Verde, Ascension, Falklands, Halley Bay, Hong Kong, with partner stations in Canada, Spitsbergen, Bolivia, S. Africa, India, Rwanda and Malaysia. Flask or bag sampling (methane, 13C and D/H isotopes) will be at these stations and at a number of continental stations in S. America, Africa and S, SE and E Asia, with offline measurement in the UK. A D/H measurement facility will be set up. The UK FAAM aircraft will carry out flights across the Atlantic tropics, from Azores to Cape Verde to Ascension. 2. Process Studies will address the largest information gaps in the global budget. Tropical emission fluxes and isotopic signatures are not well constrained. Tropical campaigns will be in wetlands in Amazonia, Africa, India and SE Asia, and C4 savanna biomass burn regions. Poorly understood anthropogenic sources will be studied in Kuwait and S, SE and E Asia. Characteristic isotopic signatures of regional emissions will be determined by inexpensive Keeling plot studies, to support global and regional modelling. Land surface modelling and satellite studies will study emissions and responses to change in temperature and precipitation. Major sink processes will be investigated in the tropical atmosphere, with vertically and latitudinal resolved OH and Cl budget studies by the FAAM aircraft, and quantification of tropical methanotrophy.3. Modelling will be used to derive regional and global fluxes, apportioned by source type and geography using integrated in situ and remote sensing observing systems. We will carry out regional trajectory studies using models like NAME to assess regional emissions. Global modelling using 3D models like UKCA will test synthetic estimates of the methane mole fraction and isotopic record. Global inverse modelling for mole fraction, 13C and D/H will be used to estimate fluxes by geographic source and source type, including a comprehensive assessment of the uncertainties that remain once all available observations have been used.4. Integrative studies will use the results from the project to test top-down and bottom-up emission estimates, and evaluate the responses of the global methane budget as it responds to climate change. The project will invest in a state of the art UK greenhouse gas monitoring network as a legacy after the project has ended.

自2007年以来，大气甲烷的浓度一直在急剧上升，原因是尚未完全理解的原因，并且在未来的气候项目中应如何对待它的不确定性。总体而言，自2007年以来的增长与全新世中最大的增长事件相当。在热带和南半球的集中度上升最大，迄今为止的同比增长最高。强劲的增长在2015年持续。碳同位素证据表明，增加的增加是由于来源主要是由于生物源的主要生物源，而人性化源的变化是自然泄漏的（例如，自然气体泄漏，越来越多），并且更加紧密地扮演），更高的是），更高效果），更高的是）。这是由热带基因座上的生长所采用的，这表明增加主要是由气象变化驱动的。但是，全球甲烷预算尚未得到很好的描述。与已知损失过程平衡的排放清单（例如，从气体泄漏，火灾，垃圾填埋场，牛，湿地等）与已知损失过程保持平衡的“自下而上”估计值与通过直接测量大气评估的“自上而下的”预算显着不同。为什么不知道这种差异发生。该项目有四个组件，每个组件都有许多工作包。1。需要更好的观察结果，以支持区域和全球大气建模以得出排放的估计。该项目将支持甲烷及其同位素的英国观察网络。连续的电台将在Kjolnes（挪威），Weybourne，泽西岛，NERC Ship RRS JC Ross，Cape Verde，Aspension，Ascension，Falklands，Halley Bay，Hong Kong，Hong Kong，与加拿大，Spitsbergen，Bolivia，Bolivia，S。Africa，S。Africa，India，Rwanda，Rwanda和Malaysia的合作伙伴站。烧瓶或袋采样（甲烷，13C和D/H同位素）将在这些车站以及S. America，Africa和S，S，SE和E亚洲的许多大陆车站，在英国进行离线测量。将建立D/H测量设施。英国FAAM飞机将在大西洋热带地区进行航班，从亚速尔群岛到佛得角到升天。 2。过程研究将解决全球预算中最大的信息差距。热带发射通量和同位素特征受到良好的约束。热带运动将在亚马逊，非洲，印度和东南亚的湿地以及C4 Savanna Biomass Burn地区进行。在科威特和S，SE和E亚洲，将研究知之甚少的人为来源。区域排放的特征同位素特征将通过廉价的龙骨图研究确定，以支持全球和区域建模。陆地表面建模和卫星研究将研究对温度和降水变化的排放和反应。主要的下水道过程将在热带气氛中进行研究，FAAM飞机垂直和纬度分析OH和CL预算研究，以及热带甲烷营养的定量。3。建模将用于推导区域和全局通量，使用源类型和地理位置分配使用集成的原位和遥感观测系统。我们将使用名称等模型进行区域轨迹研究来评估区域排放。使用像UKCA这样的3D模型的全球建模将测试甲烷摩尔分数和同位素记录的合成估计。摩尔分数，13c和d/h的全局反向建模将用于估计地理源和源类型的通量，包括对所有可用观察结果一旦使用的不确定性进行全面评估。4。综合研究将利用项目的结果来测试自上而下和自下而上的排放估算，并在对气候变化的反应时评估全球甲烷预算的反应。该项目将在该项目结束后，将投资于英国最先进的温室气体监测网络。