Articles | Volume 14, issue 23
Atmos. Chem. Phys., 14, 13023–13041, 2014
Atmos. Chem. Phys., 14, 13023–13041, 2014

Research article 09 Dec 2014

Research article | 09 Dec 2014

An improved dust emission model – Part 1: Model description and comparison against measurements

J. F. Kok2,1, N. M. Mahowald2, G. Fratini3,*, J. A. Gillies4, M. Ishizuka5, J. F. Leys6, M. Mikami7, M.-S. Park9,8, S.-U. Park8, R. S. Van Pelt10, and T. M. Zobeck11 J. F. Kok et al.
  • 1Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA 90095, USA
  • 2Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14850, USA
  • 3Department for innovation in biological, agro-food and forest systems (DIBAF), University of Tuscia, Via San Camillo de Lellis snc, 01100 Viterbo, Italy
  • 4Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA
  • 5Faculty of Engineering, Kagawa University, Takamatsu, Kagawa, 761-0396, Japan
  • 6Science Division, Office of Environment and Heritage, Department of Premier and Cabinet, Gunnedah, New South Wales, Australia
  • 7Japan Meteorological Research Institute, Tsukuba, Japan
  • 8Center for Atmospheric and Environmental Modeling, Seoul National University Research Park RM. 515 San 4-2, Bongcheon-dong, Gwanak-gu, Seoul, 151-919, Korea
  • 9Weather Information Service Engine Project, Center for Atmospheric Science & Earthquake Research, 12Fl. 434 Worldcupbukro Mapo-gu, Seoul, 121-835, Korea
  • 10USDA-Agricultural Research Service, Wind Erosion and Water Conservation Research Unit, Big Spring, TX 79720, USA
  • 11USDA-Agricultural Research Service, Wind Erosion and Water Conservation Research Unit, Lubbock, TX, USA
  • *now at: LI-COR Biosciences GmbH, Siemensstr. 25A, 61352 Bad Homburg, Germany

Abstract. Simulations of the dust cycle and its interactions with the changing Earth system are hindered by the empirical nature of dust emission parameterizations in weather and climate models. Here we take a step towards improving dust cycle simulations by using a combination of theory and numerical simulations to derive a physically based dust emission parameterization. Our parameterization is straightforward to implement into large-scale models, as it depends only on the wind friction velocity and the soil's threshold friction velocity. Moreover, it accounts for two processes missing from most existing parameterizations: a soil's increased ability to produce dust under saltation bombardment as it becomes more erodible, and the increased scaling of the dust flux with wind speed as a soil becomes less erodible. Our treatment of both these processes is supported by a compilation of quality-controlled vertical dust flux measurements. Furthermore, our scheme reproduces this measurement compilation with substantially less error than the existing dust flux parameterizations we were able to compare against. A critical insight from both our theory and the measurement compilation is that dust fluxes are substantially more sensitive to the soil's threshold friction velocity than most current schemes account for.

Short summary
We developed an improved model for the emission of dust particulates ("aerosols") emitted by wind erosion from the world's deserts. The implementation of our improved dust emission model into a climate model improves its agreement against measurements. We furthermore find that dust emissions are substantially more sensitive to the soil state than most current climate models account for.
Final-revised paper