Collaborative Research: The Influence of Tropical Convection on the Evolution and Transport of the Saharan Air Layer

大气中的沙尘对云、降水和气候都有重要影响。这是由于尘埃与云层粒子和太阳辐射相互作用的结果。地球上最多尘的地方之一是撒哈拉沙漠以西的大西洋。多位研究人员已经研究了这一“撒哈拉空气层”对热带气旋和其他云系的影响。然而，该奖项下的研究将以相反的方式看待这个问题，提出这样一个问题：云和降水如何影响撒哈拉空气层？这项工作的重要性是发现尘埃是如何通过云和降水传输和重新分布的，这可能会对气候产生重大影响。通过降水从大气中去除灰尘也可能影响海洋肥力。此外，这项研究还将为下一代科学家提供培训机会。该项目的总体目标是研究对流如何通过云处理和输送影响尘埃的时空分布。将结合区域云模型、现有的飞机数据集和现有的卫星数据集，评估沙尘量及其对撒哈拉空气层的影响。研究小组提出了三个主要的科学问题，将在这个奖项中讨论：1)相对于风暴前的数量，有多少沙尘通过降水风暴的作用从大气中移走并沉积到海洋中？2)对流风暴优先在大气中重新分布沙尘，沙尘的垂直分布如何因对流风暴的通过而改变？3)沙尘的移动和重新分布对海洋肥力有什么潜在影响，以及对风暴发展的本地和下游的直接和间接辐射影响？

Dust in the atmosphere has important impacts on clouds, precipitation and climate. This is due to how the dust interacts with cloud particles and solar radiation. One of the dustiest places on Earth is the Atlantic Ocean just west of the Sahara Desert. A number of researchers have studied the effect of this "Saharan Air Layer" on tropical cyclones and other cloud systems. However, research under this award will look at the issue in reverse, asking the question: How do clouds and precipitation affect the Saharan Air Layer? The importance of this work is the discovery of how dust is transported and redistributed by clouds and precipitation, which may have a significant impact on climate. The removal of dust from the atmosphere through precipitation may also impact ocean fertilization. In addition, the research will provide training opportunities for the next generation of scientists.The overall objective of the project is to study how convection impacts the temporal and spatial distributions of dust through cloud processing and transport. The amount of dust and the impacts on the Saharan Air Layer will be assessed through a combination of regional cloud modeling, existing aircraft data sets and existing satellite data sets. The research team poses three main scientific questions that will be addressed in this award: 1) Relative to pre-storm amounts, how much dust is removed from the atmosphere and deposited to the ocean through the action of precipitating storms? 2) Where do convective storms preferentially redistribute dust in the atmosphere, and how is the vertical distribution of dust changed by the passage of convective storms? 3) What are the potential effects of the removal and redistribution of dust on ocean fertilization, and the impacts on direct and indirect radiative effects both locally and downstream of the storm development?