Greenhouse gAs Uk and Global Emissions (GAUGE)

为了最大限度地减少与大气温室气体（GHG）浓度增加相关的危险气候变化风险，作为正在进行的国际努力的一部分，2008年《气候变化法案》要求英国到2050年将其温室气体排放量在1990年的水平上至少减少80%。为了支持这种立法，必须制定方法，以减少现有国家温室气体排放估计的不确定性，并监测减排战略的效力。2010年，二氧化碳约占英国温室气体排放总量的85%，其余主要来自甲烷（CH4）和一氧化二氮（N2O）。2010年，英国二氧化碳的主要来源是能源供应、道路运输、商业和住宅；CH4的主要来源是农业和垃圾填埋场，其次是瓦斯泄漏和煤矿；N2O的主要来源为农业、工业过程和道路运输。这些排放的部门估计存在大量相关的不确定性，特别是对一氧化二氮的估计。英国温室气体和全球排放（GAUGE）的主要重点是量化英国不同部门的二氧化碳、甲烷和一氧化二氮的预算，并改善全球温室气体预算。英国的研究将把重点放在化石燃料和农业上，这是三种温室气体的两个最大来源。我们将通过将大气测量与描述温室气体排放后的运动的大气计算机模型相结合来实现这一目标。我们已经对温室气体的排放地点有了一个合理的概念，但排放的规模通常有一个很大的相关误差。根据排放类型的不同，它也可能有一个实质性的季节周期（例如农业）。因此，我们必须在一年中的不同时间和不同地点定期进行温室气体测量。英国研究飞机将提供英国温室气体预算流入和流出的大尺度三维视角，补充现有高塔的信息。高塔网络测量地表以上100-200米的温室气体，以确保采样的空气能代表更大的区域，高塔的设置是为了提供地方政府温室气体排放量的估计。作为GAUGE的一部分，我们将在这个网络中增加一个位于苏格兰边境的塔，提供有关英格兰北部、苏格兰和北海的更多信息；一座位于英格兰东南部、伦敦顺风处的高塔；我们将支持伦敦市中心BT塔上现有的仪器。伦敦东南塔和英国电信塔一起将使我们能够提供第一个来自特大城市的多年城市排放记录。我们将利用温室气体同位素来提高对化石燃料来源的了解。对农业温室气体排放的详细研究将在东安格利亚进行，使我们能够量化该部门在英国温室气体预算中的重要性。每周在北海渡轮上的测量将通过定期采样英国流出的样带来限制英国的温室气体通量。温室气体的卫星观测提供了一个独特的全球视角，将英国的排放与世界其他地区联系起来，我们将与美国宇航局合作，开发和应用新的观测数据，在英国以外的空间尺度上量化全球温室气体预算。在这一长期测量策略中，将包含量化伦敦温室气体排放的密集测量，我们将使用英国研究飞机对逆风/顺风空气剖面进行采样，验证专用卫星观测，并将城市测量与顺风原位和高塔测量联系起来。在GAUGE中，我们汇集了大气的计算机模型和世界领先的建模团队，以便将观测到的温室气体变化与潜在排放的估计联系起来。考虑到模型和数据的不确定性，将采用统计方法寻找最符合测量结果的排放量。GAUGE的主要结果将是来自英国和世界的可靠的温室气体排放估计。

To minimize the risk of dangerous climate change associated with increasing concentrations of atmospheric greenhouse gases (GHG), as part of ongoing international efforts, the 2008 Climate Change Act requires that the UK reduces its GHG emissions by at least 80% by 2050, compared to 1990 levels. To support such legislation, methods must be developed to reduce uncertainty on existing national GHG emissions estimates and monitor the efficacy of emissions reduction strategies. In 2010, CO2 represented about 85% of total UK GHG emissions, with the remainder largely from methane (CH4) and nitrous oxide (N2O). In 2010, the main UK sources of CO2 were energy supply, road transport, business, and residential; the main sources of CH4 were agriculture and landfill with small sources from gas leakage and coal mines; and the main sources of N2O were agriculture, industrial process, and road transport. There are substantial associated uncertainties with sectoral estimates of these emissions, particularly for N2O.The main focus of Greenhouse gAs Uk and Global Emissions (GAUGE) is to quantify UK budgets of CO2, CH4, and N2O from different sectors, and to improve global GHG budgets. The UK study will focus on fossil fuels and agriculture, the two largest sources of the three GHGs. We will achieve this by combining atmospheric measurements with computer models of the atmosphere, which describe the movement of GHGs after emission. We already have a reasonable idea of where GHGs are emitted but the size of the emissions typically has a large associated error. Depending on the emission type it may also have a substantial seasonal cycle (e.g., agriculture). It is therefore important we make regular GHG measurements at different times of the year and in different places. The UK research aircraft will provide the broad-scale 3-D perspective on the inflow and outflow of UK GHG budgets, complementing information from existing tall towers. The network of tall towers measure GHGs at 100-200m above the surface to ensure that the sampled air is representative of larger areas, and the towers are intentionally sited to provide estimates of GHG emissions in the Devolved Administrations. As part of GAUGE we will add to this network with a tower in the Scottish borders that provides substantially more information about the north of England, Scotland, and the North Sea; a tower over SE England, downwind of London; and we will support existing instruments on the BT tower in central London. The SE London tower and the BT tower together will allow us to provide the first multi-year record of urban emissions from a megacity. We will use GHG isotopes to improve understanding of the fossil fuel sources. A detailed study of agricultural GHG emissions will be conducted over East Anglia, allowing us to quantify the importance of this sector in the UK GHG budget. Weekly measurements aboard a North Sea ferry will provide constraints on UK GHG fluxes by regularly sampling transects of UK outflow. Satellite observations of GHGs offer a unique global perspective, linking UK emissions to the rest of the world, and we will work with NASA to develop and apply new observations to quantify global GHG budgets on a sub-UK spatial scale. Embedded in this long-term measurement strategy will be a measurement intensive to quantify London GHG emissions, where we will use the UK research aircraft to sample profiles of upwind/downwind air, validate dedicated satellite observations, and link urban measurements with downwind in situ and tall tower measurements.In GAUGE we bring together computer models of the atmosphere, and a team of world-leading modellers, in order to relate observed variations of GHGs to estimates of the underlying emissions. Statistical approaches will be used to find emissions that best agree with the measurements, taking account of model and data uncertainties. The main outcome from GAUGE will be robust GHG emission estimates from the UK and from the world.