The effects of particle formation on global aerosol and climate

颗粒数浓度是全球大气气溶胶中受约束程度最低的特性之一。我们缺乏对控制颗粒物浓度的因素的了解，这极大地限制了我们量化气溶胶对气候的影响的能力，这是最近气候变化中最重要的因素之一。这项建议涉及颗粒形成(成核)及其在控制全球颗粒数量浓度中的作用。已有许多观测证明了粒子形成对局部粒子浓度、粒子大小分布和云凝结核的重要性。利兹大学进行的全球模型计算强烈表明，颗粒形成事件对全球范围内的总颗粒浓度有很大贡献，但人们对它们对与气候相关的颗粒子集的影响知之甚少。我们将使用一个全球气溶胶模型，受大量粒子形成观测的约束，来量化新粒子对气候相关粒子的贡献。该项目的成果将是：(I)大大提高对与气候有关的颗粒物数量浓度的全球预算的理解；(Ii)模拟全球范围内的颗粒物形成的模型计划，以纳入英国的气候模型；(Iii)更好地理解与气候有关的颗粒物浓度在工业时期如何变化。科学成果和模式发展将对全球气溶胶和气候模式的进一步发展产生重大影响。特别是，他们将直接提供给NERC-Met Office UK化学和气溶胶(UKCA)项目，为英国统一模型开发新的气溶胶微物理计划。

Particle number concentration is one of the least well constrained properties of the global atmospheric aerosol. Our lack of understanding of what controls particle concentrations greatly limits our ability to quantify the effect of aerosol on climate, which is one of the most important factors in recent climate change. This proposal deals with particle formation (nucleation) and its role in controlling global particle number concentrations. Many observations have been made that demonstrate the importance of particle formation for local particle concentrations, the particle size distribution, and cloud condensation nuclei. Global model calculations conducted at Leeds strongly suggest that particle formation events contribute substantially to total particle concentrations on a global scale, but little is known about their effect on the subset of particles that is relevant for the climate. We will use a global aeroosl model, constrained by a large number of observations of particle formation, to quantify the contribution of new particles to climate-relevant particles. The outcomes of this project will be (i) a greatly improved understanding of the global budget of climate-relevant particle number concentration; (ii) model schemes to simulate particle formation on a global scale for inclusion in the UK climate model; and (iii) an improved understanding of how climate-relevant particle concentrations have changed over the industrial period. The scientific results and model developments will have a significant bearing on the further development of global aerosol and climate models. In particular, they will feed directly into the NERC-Met Office UK Chemistry and Aerosol (UKCA) project to develop new aerosol microphysics schemes for the UK Unified Model.