Abstract View
Effect of a Forest Canopy on the Spatial Distribution of Windborne Dust Concentration during a Dust Storm
BORIS KRASOVITOV, Andrew Fominykh, Avi Levy, Itzhak Katra, Ben-Gurion University of the Negev, Israel
Abstract Number: 33
Working Group: Remote and Regional Atmospheric Aerosol
Abstract
Numerous studies show that exposure to fine dust particles transported in the atmospheric surface layer during dust storms increases the risk of exacerbation of various bronchopulmonary and allergic diseases in humans. Forest canopy may absorb atmospheric particulate matter (PM) and reduce air pollution. This study investigated the impact of forest canopy on the spatial distribution of PM10 concentration following dust events in a region that is subjected to frequent dust storms. The developed model considers the interaction between the open area on the windward side of the forest, forest structure, and forest aerodynamics. The two-dimensional model is based on the application of theory of turbulent diffusion in the forest canopy in conjunction with model of dust particles deposition on vegetation elements. The leaf area density (LAD) distribution with height as well as dust particle size distribution are taken into account. The initial wind velocity profiles on the windward side of the forest, used in the simulations were fitted from data obtained in field measurements in the studied region. The resulted dust transport in the forest canopy was validated by comparison of theoretical results with empirical data. PM concentration measurements were conducted during dust-storm days and non-dust (clean) days inside a pine forest located in Northern Negev in Israel using portable real-time dust monitoring devices. Particle size distribution (PSD) was derived by laser particle sizer. Numerical calculations performed using the developed model showed that in high-level dust storms, PM10 concentrations in an urban environment that is located at the leeward side of the forest are reduced by 34%. Our model results of the atmospheric PM distribution show fairly good agreement with the data of the field measurements.