Continuous chemical speciation of Asian VOC emissions for understanding the growth of surface ozone in East Asia

地球表面的对流层臭氧是一种主要污染物，具有多种影响，包括健康退化，特别是肺功能和心血管系统退化，以及作物产量减少，特别是小麦、玉米和水稻产量减少。在世界许多地区，对流层臭氧正在减少，但在过去20年中，东亚的对流层臭氧迅速增加。对流层中的臭氧产生是由两种前体物质推动的：氮氧化物（NOx）和阳光下的挥发性有机化合物（VOC）。亚洲区域臭氧的普遍增加是由于这些前体排放量的总体大幅增加，特别是来自中国的排放量。虽然臭氧本身的趋势可以在地面和卫星上相对直接地检测到，但跟踪背景大气中区域NOx和VOC的长期变化在技术上更具挑战性。臭氧的产生是由于污染物被长距离提升和输送，排放的影响是跨国界的，通常会影响到顺风国家以及原始排放者。中国约克大学最近对VOC的观察表明，中国城市和工业排放的VOC和NOx的混合物异常地偏向VOC，此时控制它们将是一个非常重要的步骤。NCAS/约克大学和国家环境研究所之间的这一合作项目将开发和部署自主测量挥发性有机化合物（VOCs）的新技术，VOCs是地表空气污染物臭氧的关键前体。开发的仪器将部署在一个独特的日本研究站（波照间观测站），所产生的数据将用于确定和量化挥发性有机化合物的跨界来源（包括地理来源和部门来源），这些来源在一定程度上造成了亚洲地表臭氧最近的显著上升趋势。挥发性有机化合物的长期测量很少，而且很少的测量通常只覆盖非常有限的范围。许多关键化合物，如醇、醛和酮，以及更高分子量的碳氢化合物，如来自燃料蒸发的碳氢化合物，在WMO GAW等长期计划中仍然没有得到测量。该项目将创造一种新技术，利用先进的电子冷却方法收集和浓缩到达研究地点的空气。重要的是，空气样品中存在的大量水将被自动和再生地去除，而不会影响正在测量的VOC。这对于该项目所针对的关键化合物来说尤其困难。干燥、浓缩的空气样本将使用创新的二维气相色谱系统进行分析，该系统能够对复杂的VOC混合物进行解旋。据我们所知，这将是有史以来第一次长期部署这种工具。通过将新技术与NIES Hateruma天文台现有的世界领先测量（包括NOx）放在一起，为大气化学解释增加了额外的价值。该项目以Andrews和Saito之间的合作为基础，这项后续活动围绕日本研究基础设施的共享仪器开发和全球变化观测创建了一个长期的大气科学研究方案。该项目将发挥两个伙伴组织的现有优势，并创造一种新的技术能力，以便更广泛地加以利用。它将生成独特的新的大气成分数据集，帮助日本管理空气污染和减轻环境风险，并支持英国和日本在控制国家间空气污染跨境传播的科学方面的领导地位。

Tropospheric ozone at the Earth's surface is a key pollutant, having numerous impacts including degradation in health, particularly in lung function and cardiovascular systems and reduced crop yields, particularly for wheat, maize and rice. In many regions of the world tropospheric ozone is decreasing, but East Asia has seen rapid growth in tropospheric ozone over the past two decades.Ozone production in the troposphere is fuelled by two precursors: nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. The general increases in ozone seen regionally in Asia have been caused by large overall increases in these precursor emissions, particularly from China. Whilst the trends in ozone itself can be detected relatively straightforwardly, both at the surface and from satellites, tracking long-term changes in regional NOx and VOCs in the background atmosphere is much more technically challenging. The production of ozone occurs as pollution is lifted and transported over long distances, and the effects of emissions are trans-boundary, often impacting downwind countries as well as the original emitter.Recent VOC observations made by the University of York in China has shown that the mixture of VOCs and NOx being emitted from Chinese cities and industry is unusually skewed towards VOCs, and their control would, at this time, be a more effective policy tool than reductions in NOx.This collaborative project between the NCAS/University of York and the National Institute for Environmental Studies (NIES) will develop and deploy novel technologies for the autonomous measurement of volatile organic compounds (VOCs), key precursors to the surface air pollutant ozone. The instrumentation developed will be deployed at a unique Japanese research station (Hateruma Observatory) and the data generated used to identify and quantify the trans-boundary sources (both geographic and sectoral) of VOCs that are, in part, responsible for the significant recent upwards trends in Asian surface ozone. There are very few long-term measurements of VOCs, and what few measurements there are generally only cover a very limited range. Many critical compounds such as alcohols, aldehydes and ketones still go unmeasured in long-term programmes such as WMO GAW, as do higher molecular weight hydrocarbons, for example from fuel evaporation.The project will create a new technology, utilising advanced electronic cooling methods to collect and concentrate air arriving at the research site. Importantly, the large quantity of water present in the air sample will be removed automatically and regeneratively, without affecting the VOCs being measured. This is especially difficult for the critical compounds that this project will target.The dry, concentrated air sample will then be analysed using an innovative two dimensional gas chromatography system, able to de-convolute the complex mixture of VOCs. This would be, to our knowledge, the first ever long-term deployment of such an instrument. By co-locating the new technology alongside existing world-leading measurements made at the NIES Hateruma Observatory (including NOx), exceptional additional value is added to the atmospheric chemistry interpretation. The project builds on collaborative work between Andrews and Saito, with this follow-on activity creating a longer-term programme of atmospheric science research based around shared instrument development and global change observations from Japanese research infrastructure. The project would play to existing strengths of both partner organisations and create a new technological capability to be exploited more widely. It will generate unique new datasets on atmospheric composition that will help Japan in management of air pollution and mitigation of environmental risk, and support UK and Japanese leadership of the science that informs control of the trans-boundary spread of air pollution between countries.