Dust storms in the Sahara and Sahel: Nowcasting and its application to understanding dust emission and transport

沙尘暴是一种戏剧性的天气灾害，沙尘是地球气候系统的重要组成部分，影响辐射并与碳循环相耦合。建立沙尘暴模型的内在困难意味着，需要和有机会直接根据观测数据的正向外推，即“短时预报”进行沙尘预报，这是一种非常成功地用于对流风暴短期预报的技术。该项目将开发一个尘埃近距离预报工具，然后利用该工具填补我们在了解尘埃排放和地球尘埃循环方面的关键空白，为模型的发展提供信息。由于撒哈拉和萨赫勒地区对全球尘埃循环、脆弱人口以及地球静止轨道气象卫星提供的高质量数据具有重要意义，该项目将侧重于这两个地区。我们将首先应用数据科学技术来向前推算卫星对空气中尘埃的反演，以生成即刻预报，并对这些预报进行评估，以了解技术上的变化。利用新开发的工具，结合再分析和其他遥感产品，我们将对来源及其变异性产生新的理解，并对不同气象机制在扬尘中的作用进行新的量化。如果时间允许，作为上述发现的可能应用，我们将应用上述方法调查其他重要地区的粉尘排放，如中东沙漠和戈壁沙漠。

"Dust storms are a dramatic weather hazard, and dust is an essential component of earth's climate system, affecting radiation and coupling with the carbon cycle. The inherent difficulties in modelling dust storms mean there is a need and opportunity for dust predictions based directly on forward extrapolations of observations, i.e. "nowcasts", a technique that is very successfully used for short-range prediction of convective storms. This project will develop a tool for dust nowcasting, and then use this tool to fill key gaps in our understanding of dust emissions and the Earth's dust cycle, informing development of models.The project will focus on the Sahara and Sahel, due to their importance for the global dust cycle, vulnerable populations and the high quality data available from Meteosat, which is in geostationary orbit. We will first apply data science techniques to forward extrapolate satellite retrievals of airborne dust to generate nowcast predictions and evaluate these to understand variations in skill. Using the newly developed tool, combined with reanalyses, and other remotely-sensed products we will generate new understanding of sources, and their variability, as well as new quantification of the role of different meteorological mechanisms in dust uplift. If time allows, and as a possible application of the above findings, we will apply the above approach to investigate dust emissions from other important regions, such as the Middle East desert and the Gobi desert.