Modelling of atmospheric oxidants and aerosols: deposition, emission and chemical transformation / QUEST

地球系统由大量相互作用的部件组成。例如，大气不仅受原地过程的控制，还受陆地和海洋表面的能量流动和各种化学物质的控制。同样，大气的组成也取决于对地球表面的沉积。此外，这些过程都可能随着气候状况的变化而变化。直到最近，最好的气候模型中才包含了详细的化学方案。陆地表面过程(排放、沉积等)之间的耦合化学/气候系统已经被引入到数值模型中，尽管有所简化。然而，这些后一种相互作用对组成和气候可能非常重要。在英国气象局和国家气象局大气科学中心(NCAS)之间已经开展的一项计划的基础上，现在是英国在NERC的QUEST计划中研究地面过程对大气氧化能力和气溶胶负荷的作用的时候了，该计划旨在开发一个新的社区模式--UKCA，以研究气候和组成(气相组成和气溶胶)之间的相互作用。这项提议解决了这项任务。我们的建议将英国的相关专业知识结合在一起，主要关注四个方面。它们是：(1)制定和测试化学和气溶胶计划，以便纳入气候模式；(2)制定和测试一系列计划，以描述(尽可能以互动方式)活性痕量气体的地面排放；(3)制定和测试新的地表沉积计划；(4)将这些计划落实到气候模式中，用于研究模式系统在近期和近期与气候有关的可变性。这将允许气候变化和地表排放之间的相互作用，并充分描述该系统内发生的反馈。气候模式输出的变化将直接影响排放，因为温度、土壤水分和光照强度的变化直接影响生物源挥发性有机化合物(VOCs)的排放速率。这些排放(例如，强烈依赖于温度的异戊二烯排放)可以影响氧化能力，从而影响对流层OH，从而影响包括臭氧在内的反应性温室气体的浓度，从而完成反馈循环。二阶效应也可能很重要，例如，土壤湿度的变化或地面臭氧的增加也可能改变VOC的排放速率。我们的研究将使这些化学/气候反馈过程能够在涵盖上个世纪和下个世纪的研究中得到评估。

The earth system is comprised of a large number of interacting components. For example, the atmosphere is controlled not just by processes occurring in situ but also by fluxes of energy and a variety of chemical species from the land and ocean surfaces. Similarly, atmospheric composition also depends on deposition to the earth surface. Furthermore, these processes are all likely to change with the climate state. It is only recently that detailed chemical schemes have been included in the best climate models. Coupling between land surface processes (emissions, deposition, etc.) and the chemistry/climate system has been introduced into numerical models, albeit somewhat simplified. These latter interactions could however be very important for composition and climate. The time in now right for a major UK initiative within NERC's QUEST programme, to study the role of surface processes on atmospheric oxidizing capacity and aerosol loading, building on an initiative already underway between the Met Office and the NERC Centres for Atmospheric Science (NCAS) to develop a new community model, UKCA, to study the interaction between climate and composition (gas phase composition and aerosols). This proposal addresses that task. Our proposal brings together relevant UK expertise with four main foci. These are (1) the development and testing of chemistry and aerosol schemes to include in a climate model, (2) the development and testing of a range of schemes to describe (interactively wherever possible) surface emissions of reactive trace gases, (3) the development and testing of new surface deposition schemes, and (4) implementation of these schemes into the climate model which will be used to look at climate-related variability of the model system for the immediate past and the near future. This will allow the interaction between changing climate and surface emissions with full description of the feedbacks occurring within this system. Changes in the output of the climate model will affect emissions directly, as changes in temperature, soil moisture and light intensity have direct effects on the emission rates of biogenic volatile organic compounds (VOCs). These emissions (for example, the strongly temperature-dependent isoprene emissions) can affect oxidizing capacity, and hence tropospheric OH and so the concentration of reactive greenhouse gases, including ozone, thereby completing the feedback loop. Second-order effects may also be important, for example, changes insoil moisture or elevated ground level ozone may also alter VOC emission rates. Our study will allow these chemistry/climate feedback processes to be assessed in studies covering the last century and the coming century.