Air quality supersite triplets (UK-AQST)

空气污染是英国最严重的环境风险，导致每年200亿英镑的经济成本和严重的健康不平等。量化空气污染的变化原因促使NERC投资了三个固定的空气质量超级站点，它们位于伦敦、伯明翰和曼彻斯特的城市背景位置，通过UKRI SPF项目OSCA运营。与此同时，即将（2021年初）修订的世卫组织指南将在新的《环境法案》中为新的国家空气质量目标提供信息，这些目标可能反映人口平均暴露量。空气质量差是由于排放、气象和大气过程的相互作用造成的，影响了现有物种的负荷和毒性。两个关键的不确定性是：1、交通和城市排放之间的平衡，以及空气中已经存在的来自逆风的污染物，这是改善空气质量的区域和国家政策责任的关键空间变化的排放与影响空气质量的化学处理之间的相互作用，包括农业排放和运输变化对净零排放的作用。在这里，我们将开发新的英国社区能力来解决这些不确定性：灵活配置空气质量超级三重，跨越逆风，路边和城市观测能力。UK-AQST包括现有的固定超级站点（城市），以及两个移动“超级站点”来研究（例如）逆风农村和路边空气成分。这两个装置将位于可持续移动平台内（一辆电动货车，一辆拖车，以实现最大的灵活性），按照国家标准运行，并产生开放获取的数据。这些超级站点不是传统的监测站，它们将包括高度复杂的仪器，监测大气过程中的关键物种，如氨（气溶胶形成的关键）、挥发性有机化合物（臭氧、二次有机气溶胶和新颗粒形成的关键），以及微量金属、纳米粒子和颗粒组成，以及受管制的气体污染物。通过使用三重站点配置（农村、城市、路边），不仅可以测量城市和路边的浓度增量，还可以以前所未有的细节观察污染空气形成关键二次污染物（如硝酸盐和二次有机颗粒）和新形成的纳米颗粒的过程，从而了解过程。这三项观测将在量化空气污染源和过程的科学能力方面产生一个根本性的变化，从而巩固英国在这一领域的世界领先地位。它将产生具有重大影响的政策相关科学，特别是在为空气质量政策提供信息方面，包括对进口排放核算方法的验证，并在英国和全球范围内应用于类似的挑战。

Air pollution is the most significant environmental risk in the UK, leading to economic costs of £20b/y and significant health inequalities. Quantifying the changing causes of air pollution motivated NERC investment in three fixed air quality supersites - located in urban background locations within London, Birmingham and Manchester, operated via the UKRI SPF project OSCA. In parallel, the forthcoming (early 2021) revision of WHO guidelines will inform new national air quality targets, within the new Environment Bill, which are likely to reflect population-averaged exposure.Poor air quality arises from the interaction of emissions, meteorology and atmospheric processes, affecting the loading and toxicity of the species present. Two key uncertainties are 1 The balance between traffic and urban emissions, and pollutants already present in the air arriving from upwind, key to the regional and national policy responsibility for improving air quality.2 The interaction between spatially varying emissions and chemical processing affecting air quality, including the role of agricultural emissions and transport shifts for Net Zero. Here, we will develop new UK community capability to address these uncertainties: Flexibly configurable air quality supersite triplets, spanning upwind, roadside and urban observational capability. UK-AQST comprises the existing fixed supersites (urban), augmented by two mobile "supersites" to study (for example) upwind rural and roadside air composition. The two units will be located within sustainable mobile platforms (one electric van, one trailer for maximum flexibility) operated to national standards and producing open-access data.The supersites are not traditional monitoring stations - they will comprise highly sophisticated instruments which monitor key species in atmospheric processes such as ammonia (key to aerosol formation), VOCs (key to ozone, secondary organic aerosol and new particle formation), as well as trace metals, nanoparticles and particle composition in near-real time, in addition to regulated gas pollutants. By using a triplet site configuration (rural, urban, roadside), not only can urban and roadside concentration increments be measured, the processing of polluted air to form key secondary pollutants such as nitrate and secondary organic particles, and freshly formed nanoparticles can be viewed in unprecedented detail to yield process understanding.The triplet observations will generate a step-change in scientific capability for quantifying air pollution sources and processes at a fundamental level, thus consolidating UK's world-leading position in this field. It will produce policy relevant science with significant impact, particularly in informing air quality policy including the validation of approaches accounting for imported emissions, with applications across the UK and for analogous challenges globally.