U017-13
A modeling perspective on Pleistocene landscape evolution and dust production in the Hami Basin, China

Tuesday, 15 December 2020: 06:11
Jordan Abell, Lamont-Doherty Earth Observatory, Palisades, NY, United States, Stefan R. Rahimi, University of California Los Angeles, Institute of the Environment and Sustainability, Los Angeles, CA, United States, Alex Pullen, Clemson University, Department of Environmental Engineering and Earth Sciences, Clemson, United States, Zachary J Lebo, University of Wyoming, Atmospheric Science, Laramie, WY, United States, Dehai Zhang, China University of Geosciences Wuhan, Center for Global Tectonics, School of Earth Sciences, Wuhan, China, Paul A Kapp, Univ Arizona, Tucson, AZ, United States, Lucas Gloege, Columbia University, Department of Earth and Environmental Engineering, New York, NY, United States, Sean Ridge, Lamont-Doherty Earth Observatory of Columbia University, New York, NY, United States, Junsheng Nie, Lanzhou University, College of Earth and Environmental Sciences, Lanzhou, China and Gisela Winckler, Columbia University, Department of Earth and Environmental Sciences, New York, NY, United States
Abstract:
Accurate characterization of dust emission is essential for understanding past climates. Most paleoclimate models account for shifts in vegetation, soil moisture, and ice cover, but largely ignore changes in landscape evolution. Central Asia, a region containing abundant ever-evolving stony deserts today, offers the potential to study the effects of varying surficial geology on dust production and regional climate. Here, the Weather Research and Forecasting model coupled to an aerosol chemistry model (WRF-Chem) is used to quantify the effects of arid landscape evolution on boundary layer conditions, dust production, and radiative properties in the western Gobi Desert, China. Altered surface roughness, sediment erodibility, and albedo, representative of Plio-Pleistocene conditions in the Hami Basin, combine to produce up to a ~44% increase, ~59% increase, and ~4.4 W m-2 change in springtime averaged wind speeds, dust loading, and downwelling radiation, respectively, over the perturbed region of the Hami. These modeling results, along with geomorphological evidences from the western Gobi Desert, suggest that the Hami Basin (and likely other stony deserts of Central Asia) were larger dust producers during cooler intervals of the Pleistocene.
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