Monitoring dust emission from the western United States is important on both local and regional scales because of the effects on air quality, human health and safety, ecosystem function, and water availability. The Sources, Compositions, and Effects of Atmospheric Dust from American Drylands project develops and maintains a catalog of dust-emission events in the western United States that are visible in satellite imagery. The overall objectives are to determine the location, size, frequency, duration, and transport patterns of dust events in western North America. Although this catalog has broad applicability, it primarily complements ongoing work focusing on the effects of dust deposited on mountain snow cover.
Dust on mountain snow cover changes snow albedo and enhances the absorption of solar radiation, thereby increasing rates of snowmelt, which leads to earlier-than-normal spring runoff and overall smaller late-season water supplies for tens of millions of people and industries in the American West. Identification of these dust-source areas guides field work and subsequent studies to understand dust properties that affect snow albedo. The ability to link deposited dust to dust-source areas may inform mitigation of dust emissions that diminish Colorado River water resources.
The MODIS image to the left documents dust emission from many point sources along the Little Colorado River on the southern Colorado Plateau. The MODIS image to the right shows dust on snow throughout the Rocky Mountains, especially in the San Juan Mountains in Colorado. The dust in this image includes the dust emitted from the southern Colorado Plateau shown in the image to the left.