Global Modelling of Aerosols and Chemistry in Support of SOLAS-UK

自然气候系统中最重要的反馈之一涉及海洋表面气体的排放。一种重要的气体，二甲基硫化物，会导致空气中颗粒的形成（气溶胶）。这些粒子强烈地影响着云的性质，而云又在控制全球气温方面发挥着重要作用。在未来的气候中，二甲基硫化物的排放量可能会有所不同。因此，了解这种气体排放的变化如何影响海洋大气中的气溶胶是很重要的。海洋大气中粒子的化学组成和物理性质是由发生在全球尺度上的一系列复杂过程（包括气体化学、粒子形成、去除和输送）所决定的。目前对这些过程的量化还很差。在这个项目中，我们将使用一个新的全球气溶胶（大气中的小颗粒）模型来量化化学和气象过程如何控制颗粒的大小、化学成分、时空变化以及它们形成云的能力。这项工作的主要成果将是全面评估我们对海洋气溶胶的认识，以及全面评估全球气溶胶/化学模型。我们还将使用这个详细的模型来开发英国气候模型的改进版本，以确保它包含进行现实气候模拟所必需的气溶胶过程。我们的部分工作将致力于为与密集的野外活动相关的海洋地区提供大小和成分分辨的气溶胶预测，从而帮助分析其他项目的观测结果。

One of the most important feedbacks in the natural climate system involves the emission of gases from the ocean surface. One important gas, dimethyl sulphide, leads to the formation of particles in the air (aerosol). These particles strongly influence the nature of clouds, which in turn play a large part in controlling global temperatures. Emissions of dimethyl sulphide may be different in a future climate. It is therefore important to understand how changes in the emission of this gas affect the aerosol in the marine atmosphere. The chemical composition and physical properties of particles in the marine atmosphere are shaped by a complex range of processes (involving gas chemistry, particle formation, removal and transport) occurring on global scales. These processes are poorly quantified at present. In this project we will use a new global model of aerosols (small particles in the atmosphere) to quantify how chemical and meteorological processes control the size of the particles, their chemical composition, variability in time and space, and their ability to form clouds. The principal outcomes of this work will be a complete assessment of our understanding of marine aerosols as well as a fully evaluated global aerosol/chemistry model. We will also use this detailed model to develop an improved version of the UK climate model to make sure that it contains the aerosol processes necessary to undertake realistic climate simulations. Part of our effort will be dedicated to producing size and composition-resolved aerosol predictions for oceanic regions of relevance to intensive field campaigns, thereby aiding the analysis of observations made in other projects.