Aerosol Coupling in the Earth System (ACES)

向大气中排放痕量物质可对环境产生各种影响，从释放地对健康的直接影响到对大气成分和气候的全球影响。有机化合物，如碳氢化合物，从自然和人类影响的来源大量排放，并导致许多广为人知的环境现象，例如光化学烟雾和全球气候变化。据估计，每年约有20亿吨有机物质排放到大气中。自然来源包括植被(例如森林)的排放，当考虑到全球总排放量时，这类来源占主导地位。人为影响的排放来自许多来源，特别是公路运输、汽油和其他燃料的分配、溶剂的使用和一些工业过程。在人口稠密的地区，这种来源通常是有机物质进入大气的主要输入。已知一些排放的有机化合物直接危害人类健康，例如作为致癌物质。然而，更广泛的影响来自大气中有机物质的化学处理，这导致了各种产品的产生，有时被称为“二次污染物”。这些氧化过程的一个副产品是产生不稳定或高度溶解的有机氧化产物，这可能会导致空气中的颗粒物或气溶胶的质量。大气中的气溶胶通过光和紫外线辐射的散射和吸收对能见度和气候有重要影响，还可能对健康产生直接影响，因为细颗粒物可以吸入肺部。拟议工作的目的是：(1)提高我们对世界森林地区排放的天然碳氢化合物化学加工产生气溶胶的基本过程的了解；(2)评估这些气溶胶对大气成分、气候和降雨量的影响；(3)评估土地利用的变化对上述过程和影响的影响。这将通过实验室中的实验研究、热带森林地区的观测研究和利用大气数值模型进行的评估研究相结合来实现。

The emission of trace materials into the atmosphere can have a variety of influences on the environment, ranging from immediate health impacts in the locality of the release to global effects on atmospheric composition and climate. Organic compounds, such as hydrocarbons, are emitted in large quantities from both natural and human-influenced sources, and contribute to many of the well-publicised environmental phenomena, for example, photochemical smog and global climate change. It is estimated that about 2 billion tonnes of organic material are emitted into the atmosphere each year. Natural sources include emissions from vegetation (e.g., forests), and such sources dominate when total global emissions are considered. Human-influenced emissions result from many sources, in particular road transport, distribution of petrol and other fuels, solvent usage and some industrial processes. In populated regions, such sources usually represent the major input of organic material into the atmosphere. Some emitted organic compounds are known to be directly detrimental to human health, for example as carcinogens. However, a much wider impact results from the chemical processing of organic material in the atmosphere, which leads to the generation of a variety of products, sometimes known as 'secondary pollutants'. One by-product of these oxidation processes is the generation of involatile or highly soluble organic oxidation products which can contribute to the mass of airborne particles or 'aerosols'. Aerosols in the atmosphere have an important influence on visibility and climate, through the scattering and absorption of light and UV radiation, and can also have direct health implications because fine particles can be inhaled into the lung. The proposed work aims (i) to improve our understanding of the fundamental processes involved in the formation of aerosols from the chemical processing of natural hydrocarbons emitted from forested regions of the world: (ii) to assess the impact of those aerosols on atmospheric composition, climate and rainfall: and (iii) to assess the impact of changes in land use on the above processes and impacts. This will be achieved using a combination of experimental studies in laboratory chambers, observational studies in a tropical forested region, and assessment studies using numerical models of the atmosphere.