The role of anthropogenic aerosol in near-future sub-Saharan precipitation

人为气溶胶在近期撒哈拉以南地区降水中的作用

• 批准号: 2740981
• 金额: --
• 依托单位: University of Reading
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2740981
• 关键词: role; anthropogenic; aerosol; near; future

Sub-Saharan Africa is densely populated and highly sensitive to climate change. West Africa has experienced both prolonged periods of drought and increased flooding over the last 50 years, and there is substantial concern that intensifying climate risk will exacerbate existing vulnerabilities. Although historical Sahel drought has been attributed to aerosol increases, African precipitation responses to aerosol changes are relatively unexplored. There is almost no existing literature exploring the impact of aerosol changes on East African rains. There are large uncertainties in projections of African precipitation due to differences between models. Differences in the simulation of the atmospheric response to forcing, and the response to aerosol forcing in particular, play an important role in this uncertainty. Aerosol emissions from remote regions have been implicated in driving historical changes in several African regions, while some of the largest uncertainties in future emissions are also found over Africa. Much of the current requirement for projection information for Africa focuses on near-term, 10-40-yr time scale, climate adaptation. Changes in short-lived pollutants like aerosols play a much stronger role than greenhouse gases in driving the spread of near-term projections. In this project, the role of aerosol in African climate projections, and the uncertainties in these projections, will be explored through three research questions: - What is the response of sub-Saharan African climate to potential future anthropogenic aerosol changes? - What are the relative roles of local and remote aerosol changes, and different aerosol species, in climate projections for Africa? - What are the mechanisms for West African and East African precipitation responses to regional aerosol forcing? Do these mechanisms depend on model climatology, model process representation, or internal variability? To address these questions, the student will have access to a new set of coupled model experiments, designed to explore the role of aerosol in near-term projections and be easily comparable to projections typically used in decision making. The student will perform idealised experiments to aid diagnosis of important mechanisms. There is the potential to expand these experiments to quantify the role of model biases, or the role of internal variability, in the response to aerosol changes. This project is an opportunity for the student to become an expert in a scientific topic that will become increasingly relevant as climate change, and societal responses to increased climate risk, progress. The regions where precipitation changes are expected have a large population and are undergoing considerable development with a need for mitigation. The project will thus potentially inform the next assessment of the IPCC.

撒哈拉以南非洲人口稠密，对气候变化高度敏感。过去50年来，西非经历了长期干旱和洪灾加剧，人们严重关切气候风险的加剧将加剧现有的脆弱性。尽管历史上的萨赫勒干旱被认为是气溶胶增加所致，但非洲降水对气溶胶变化的反应相对较少。目前几乎没有任何文献探讨气溶胶变化对东非降雨的影响。由于模型之间的差异，对非洲降水的预测存在很大的不确定性。在模拟大气对强迫的反应，特别是对气溶胶强迫的反应方面的差异，在这种不确定性中起着重要的作用。偏远地区的气溶胶排放被认为推动了几个非洲区域的历史变化，而未来排放的一些最大不确定性也出现在非洲上空。目前对非洲预测信息的大部分需求侧重于近期、10-40年的时间尺度、气候适应。在推动短期预测的传播方面，气溶胶等短期污染物的变化比温室气体发挥的作用要大得多。在这个项目中，将通过三个研究问题探讨气溶胶在非洲气候预测中的作用以及这些预测中的不确定性：-撒哈拉以南非洲气候对未来潜在的人为气溶胶变化的反应？-当地和远程气溶胶变化以及不同气溶胶种类在非洲气候预测中的相对作用？-西非和东非降水对区域气溶胶强迫的反应机制是什么？这些机制是否依赖于模型气候学、模型过程表示或内部可变性？为了解决这些问题，学生将有机会接触到一套新的耦合模型实验，旨在探索气溶胶在短期预测中的作用，并容易与通常用于决策的预测相比较。学生将进行理想化的实验，以帮助诊断重要的机械装置。有可能扩大这些实验，以量化模型偏差的作用，或内部可变性在气溶胶变化反应中的作用。这个项目为学生提供了一个成为科学主题专家的机会，随着气候变化和社会对气候风险增加的反应的进展，科学主题将变得越来越相关。预计降水量变化的区域人口众多，正在经历相当大的发展，需要缓解。因此，该项目可能会为气专委的下一次评估提供信息。