Making a Dust Source Map: Can We Build, Implement, and Learn From a Reflectance Derived Sediment Supply Map in the Unified Forecast System (UFS)?

Mineral dust is an important part of the climate system we live in. Dust hotspots in deserts and arid regions emit tons of dust annually, influenced by local meteorology and soil characteristics. As one of the most abundant aerosols, it is important to characterize and define the climate and human impacts of dust. To do this, we must first understand how much dust there is in the atmosphere and model its emission and transport correctly. Using the Unified Forecast System (UFS), we examine the impact of a new sediment supply map. Here, we look at how a global, non-static sediment supply map with information about fines, alluvial sediment, dunes, and sand information can be generated and applied within the FENGSHA dust emission scheme in the UFS. Further, we compare and explore model aerosol optical depth information to satellite data for the “Godzilla” dust storm of 2020. We show that by building the Sediment Supply Map using information about dunes, sand, alluvials, and fines, we can more accurately represent the two most important characteristics of dust emission—how much is emitted, and where it comes from. The reflectance derived sediment supply map presented here contains areas of improved accuracy of sediment availability, and adds areas of supply not identified previously. This information is important for improving model parameterization and accuracy.