Investigating long-term changes in European air quality in the satellite era

社会越来越意识到空气质量差的危害。空气污染物，如臭氧（O3）、二氧化氮（NO2）和颗粒物（PM2.5和直径分别小于2.5微米和10微米的10颗粒），可对人类健康产生重大影响。暴露于明显升高的地表臭氧会导致呼吸功能下降和心血管问题。据估计，英国糟糕的空气质量每年导致大约4万人过早死亡，每年给社会造成85亿至202亿英镑的损失。近几十年来，欧洲的空气质量立法减少了许多空气污染物，如二氧化氮（NO2）和颗粒物（PM2.5——直径小于2.5微米的颗粒）。然而，许多观测研究表明，西欧的二次污染物臭氧（O3）在地表和自由对流层一直在增加。该项目将利用大气化学模型和对流层臭氧的卫星观测来调查哪些过程（例如前体气体的排放和/或远距离输送）正在迫使西欧臭氧浓度增加。由此产生的工作将有助于量化人为活动（如排放）在多大程度上推动了臭氧的趋势，以及在多大程度上可以用自然过程（如平流层-对流层交换）来解释。该项目将提供数值模拟和卫星数据分析方面的优秀培训。它涉及到一个非常热门的公共卫生问题，是一个非常活跃的研究领域。

Society is becoming increasingly aware of the dangers of poor air quality. Air pollutants, such as ozone (O3), nitrogen dioxide (NO2) and particulate matter (PM2.5 and 10-particles with diameters of less than 2.5 and 10 um, respectively), can have significant impacts on human health. Exposure to significantly elevated levels of surface ozone can cause reduced respiratory function and cardiovascular problems. It is estimated that poor UK air quality results in approximately 40,000 premature deaths annually and costs society £8.5-20.2 billion per year.Over recent decades, European air quality legislation has led to the reduction of many air pollutants such as nitrogen dioxide (NO2) and particulate matter (PM2.5 - particles with diameters of less than 2.5 um). However, many observational studies have shown that in Western Europe the secondary pollutant ozone (O3), has been increasing at the surface and in the free troposphere. This project will use atmospheric chemistry modelling and satellite observations of tropospheric O3 to investigate which processes (e.g. emission of precursor gases and/or long range transport) are forcing these increases in Western European O3 concentrations. The resulting work will help quantify to what extent anthropogenic activities (e.g. emissions) are driving the trend in O3 and how much can be explained by natural processes (for example stratospheric-tropospheric exchanges). This project will provide excellent training in numerical modelling and satellite data analysis. It relates to a very topical public health issue and is a very active area of research.