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

大气中的尘埃对云层、降水和气候都有重要影响。这是由于尘埃如何与云粒子和太阳辐射相互作用。地球上灰尘最多的地方之一是撒哈拉沙漠以西的大西洋。许多研究人员研究了这个“撒哈拉空气层”对热带气旋和其他云系统的影响。然而，该奖项下的研究将从相反的角度看待这个问题，提出这样的问题：云和降水是如何影响撒哈拉空气层的？这项工作的重要性在于发现了尘埃是如何通过云和降水运输和重新分布的，这可能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施肥。此外，该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的处理和传输影响尘埃的时空分布。将通过结合区域云模型、现有飞机数据集和现有卫星数据集来评估沙尘的数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，将在这个奖项中得到解决：1)相对于风暴前的数量，有多少灰尘从大气中移除，并通过降水风暴的作用沉积到海洋中？2)对流风暴优先重新分配大气中的粉尘，对流风暴的通过如何改变粉尘的垂直分布？3)沙尘的清除和再分配对海洋施肥的潜在影响，以及对局地和风暴发展下游的直接和间接辐射效应的影响？

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?