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
Received: 12 Dec 2013 – Discussion started: 11 Mar 2014
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.
Revised: 17 Sep 2014 – Accepted: 21 Oct 2014 – Published: 09 Dec 2014
Kok, J. F., Mahowald, N. M., Fratini, G., Gillies, J. A., Ishizuka, M., Leys, J. F., Mikami, M., Park, M.-S., Park, S.-U., Van Pelt, R. S., and Zobeck, T. M.: An improved dust emission model – Part 1: Model description and comparison against measurements, Atmos. Chem. Phys., 14, 13023-13041, doi:10.5194/acp-14-13023-2014, 2014.