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?
