Impact of Suburban Planted Forests on the Dispersion of Carbon-Based Aerosol Plumes from Industrial Sources
BORIS KRASOVITOV, Avi Levy, Itzhak Katra, Ben-Gurion University of the Negev, Israel
Abstract Number: 165
Working Group: Urban Aerosols
Abstract
The carbon-based PM2.5-10, typical of industrial emissions, is a major source of air pollution, negatively affecting human health, increasing the risk of worsening respiratory and allergic diseases, and leading to problems such as acid rain and smog. Planted forests in suburban areas can modify the velocity and spatial distribution of aerosol pollutants emitted by industrial sources, affecting the dispersion of plumes. The present study suggests the numerical model of Particle Deposition on a Forest Canopy (PDFC) supplemented by parameterizing the average collection rate based on the CFD model. The turbulent momentum and mass transfer in and above the forest canopy are described by a gradient turbulent transfer model using a modified Blackadar model for turbulent viscosity within the forest canopy. 3D numerical modeling of the particulate flow utilizing discrete phase models based on the Eulerian-Lagrangian technique has been carried out. The vegetation element is considered as a prolate ellipsoid approximating in shape to a leaf of Aleppo pine (Pinus halepensis), the dominant tree species in Northern Negev (Israel). The analyses of the obtained results are performed for different meteorological conditions and atmospheric stability. The performed numerical analysis showed that a significant reduction in PM10 concentrations on the leeward side of the forest occurs with unstable stratification due to a combination of effective deposition on the crown and intense atmospheric mixing. With neutral stratification, the effect is moderate, and with stable stratification, the concentration remains high due to weak dispersion. Thus, forest plantations are most effective in reducing air pollutants under daytime convective conditions. The results of this study highlight the importance of forest plantations in controlling air pollution from industrial sources in adjacent urban areas.