|Address:||G5703, 5/F, Yeung Kin Man Academic Building (YEUNG),
City University of Hong Kong,
Tat Chee Avenue, Kowloon, Hong Kong SAR
Division of Atmospheric Sciences
Desert Research Institute, Reno, Nevada, USA
School of Energy and Environment
City University of Hong Kong
The DRI Lagrangian Particle Dispersion Model is a particle-based Lagrangian trajectory type coupled with a meteorological wind field model. Wind and turbulence fields are estimated using the CALMET diagnostic meteorological model constrained with surface stations, upper air soundings, buoys, and North American Reanalysis data. In-grid-cell emissions are based on relationships between particle mass flux and friction speed developed from in-situ measurements using the Portable In-Situ Wind ERosion Lab (PI-SWERL). The dispersion model is based on the Langevin formulation and includes turbulent diffusion and stochastic particle motion in the inertial sub-range, and assumes particles are discrete units and neglects deposition. The model estimates diffusion of particles from an initial particle release that scales using the friction speed-variable emissions relationships. This dispersion model has been adapted to operate at very high spatial resolution (20 m grid cells) as it is being applied to examine the emission and transport of dust from a coastal dune system in California, the Oceano Dunes, and must consider the complex flow over the dunes. Results were tested at two independent-downwind locations, with very positive correlations for horizontal wind speed and receptor particle mass concentrations. Evaluations against observations made during mean flow conditions as well as for elevated dust events suggest that the model framework is capable of capturing spatial and temporal characteristics of dust concentration mean diurnal variability and outbreaks due to elevated wind speeds. Performance metrics will be presented as well as how the model is being used to guide management decisions on where to place mitigation measures as well as evaluating how these mitigations may affect dust concentrations at critical receptor sites.
Dr. Jack Gillies is a Research Professor in the Division of Atmospheric Sciences at the Desert Research Institute in Reno, Nevada, USA, which is part of the Nevada System of Higher Education. Jack received his PhD in Physical Geography at the University of Guelph, Canada in 1995. He has 30 years’ experience in the research field of aeolian processes. Currently his research focuses on the physics of sand transport and fugitive dust emission by wind and anthropogenic processes. This work covers the full spectrum of the system from the controls on the initiation of sediment movement and the transport phase through to the deposition process. His most-recent research has involved studying how porous roughness elements affect wind flow and interact with the transport of sediment using wind tunnel and field studies. This research is designed to aid in our understanding of how vegetation affects flow and sediment transport, and also how engineered roughness and managed vegetation covers may be optimized to reduce dust emissions from susceptible surfaces. Dr. Gillies has collaborated in the design, construction, and utilization of laboratory and portable field wind tunnels and the attendant specialized instrumentation for measuring surface shear stress, and emission rates of particulates from various types of surface that are susceptible to wind erosion and fugitive emissions. He has also been involved in developing monitoring systems for measuring particulate matter concentrations and particle size distributions for use in remote, logistically difficult situations. He has carried out field work in dryland areas across the globe including: the southwest United States, west and southern Africa, Canada, and Antarctica.