Aerosol Coupling in the Earth System (ACES)

微量物质排放到大气中可对环境产生各种影响，从释放地点的直接健康影响到对大气成分和气候的全球影响。碳氢化合物等有机化合物从自然和人类影响的来源大量排放，并造成许多广为宣传的环境现象，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。自然来源包括来自植被（如森林）的排放，在考虑全球排放总量时，这些来源占主导地位。受人类影响的排放有许多来源，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，这类来源通常是有机物质进入大气的主要来源。已知一些排放的有机化合物对人体健康直接有害，例如致癌物。然而，大气中有机物质的化学处理产生了更广泛的影响，导致产生各种产品，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难溶性或高度可溶性的有机氧化产物，这可能导致空气中颗粒或“气溶胶”的质量增加。大气中的气溶胶通过对光和紫外线辐射的散射和吸收，对能见度和气候产生重要影响，而且由于细颗粒可被吸入肺部，也可能对健康产生直接影响。拟议的工作旨在(i)提高我们对世界森林地区排放的天然碳氢化合物的化学加工过程中气溶胶形成的基本过程的理解；（ii）评估这些气溶胶对大气成分、气候和降雨的影响；（iii）评估土地利用变化对上述过程和影响的影响。这将通过综合利用实验室室内的实验研究、热带森林地区的观测研究和利用大气数值模式的评估研究来实现。

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.