Aerosols affect the Earth’s radiation balance directly by absorbing and scattering sunlight and by modifying the duration of snow and ice through atmospheric and albedo decreases. As the direct radiative impact depends on aerosol composition and size, characterization of the aerosol population is necessary, both within the atmospheric column and on the snow surface. Furthermore, understanding the source region of the aerosol is critical for emission control policy.
Via recent seed funding from the Society, Water and Climate initiative, we are investigating the economic impact of increasing spring dust events on ski areas in the Western U.S. This funding initiative has brought together expertise at the University of Utah in atmospheric science (Dr. A. Gannet Hallar and Dr. John Lin), geography (Dr. McKenzie Skiles) and economics (Dr. Haimanti Bhattacharya). Thus far, we have made measurements of dust both on the surface of the snow and within the atmosphere in Little Cottonwood Canyon near the town of Alta, UT. Via these measurements we identified a significant dust event. In the past source regions in central and southern Utah, such as the Milford Flat fire scar, have been identified as source regions for dust on snow in the Wasatch. Using the modeling expertise in our group, we traced this dust back to the Great Salt Lake Basin and potentially the dry lake bed of the Great Salt Lake. We have also combined expertise to help validate space-based remote sensing products of dust on snow. Finally, we are collaborating on a review paper pertaining to the topic of increasing dust in the Western U.S.