Using satellites to map the spatial characteristics of urban air pollution from aerosols at a time of climate change, health choices and pandemics

空气中的颗粒物在环境科学中起着关键作用，对气候和空气质量有着重要影响。颗粒物（气溶胶）是造成空气质量差的最重要因素之一，估计每年有400万人死亡，其中大部分是由空气中的颗粒物引起的心血管和呼吸系统疾病造成的。高密度气溶胶（烟雾）与新冠肺炎传播和发病率数据的相关性表明，至少在污染、新冠肺炎脆弱性（如呼吸系统）、城市密度和疾病传播之间存在统计学联系。然而，气溶胶是高度复杂和可变的，特别是在城市中，由于其不同的来源（汽车尾气，工业，燃料燃烧等）。大气反应。现有的地基网络可以提供一个很好的时间，但只有一个非常不完整的城市气溶胶分布的空间视图。对许多城市来说，需要一种新的观测形式，向所有人提供气溶胶空气质量信息，并将改变我们评估气溶胶分布及其可能的健康影响的能力，卫星上的光学仪器是从空间监测气溶胶的重要资源。最近发射的Sentinel-2可以从根本上改变我们对城市气溶胶的研究方法，使我们能够在数十米（可能是10米）的前所未有的尺度上获得气溶胶信息。这是确定不同气溶胶源（道路、工业设施等）的相关尺度，在这个项目中，科学的挑战需要新的方法来获得气溶胶浓度，所以学生将创建一个新的气溶胶数据集，具有非常高的空间分辨率，并使用它来挑战我们目前对城市气溶胶的理解。接下来令人兴奋的科学将引起其他科学家、公众和政策制定者的极大兴趣。研究结果将发表在高质量的期刊上，并与政府和地方当局分享，特别是通过环境、食品和农村事务部的联系。CENTA的合作伙伴在这类研究方面有很大的优势，因此该项目将在CENTA之间建立联系。

Airborne particles play a critical role in environmental science with major implications for climate and air quality. Particulate matter (aerosols) is one of the most important factors for poor air quality and most of the estimated 4 million excess deaths per year stem from cardiovascular and respiratory diseases caused by particulate matter in the air. Correlations of high densities of aerosols (smog) with transmission and morbidity data from Covid-19 have suggested statistical links, at least, between pollution, Covid vulnerability (e.g. respiratory), urban density and disease transmission. However, aerosols are highly complex and variable, especially in cities, due to their diverse sources (vehicle exhaust, industry, fuel-burning etc.) and atmospheric reactions. Existing ground-based networks can provide an excellent temporal but only a very incomplete spatial view of urban aerosol distributions. For many cities, a new form of observation is required to provide aerosol air quality information to all and would transform our ability to assess aerosol distributions and their likely health impacts.Optical instruments on satellites are an important resource to monitor aerosols from space. The recently launched Sentinel-2 can fundamentally change our approach to urban aerosols by allowing us to derive aerosol information on an unprecedented scale of tens of meters (potentially 10 m). This is the relevant scale to pinpoint different aerosol sources (roads, industrial facilities etc.), to diagnose aerosol variations across urban conurbations and the impact of transport pathways within a city.In this project, the challenges of the science require new methods to derive the aerosol concentrations so the student will create a novel aerosol dataset with very high spatial resolution and use it to challenge our current understanding of urban aerosols. The exciting science that follows will be of great interest to other scientists, to the public and to policy makers. Results will be published in high quality journals and shared with government and local authorities, particularly through contacts in the Department for Environment, Food and Rural Affairs. CENTA partners have some great strengths in this type of research so the project will build links across CENTA.