Improving Simulation of Fine Dust Surface Concentrations Over the Western United States by Optimizing the Particle Size Distribution

TitleImproving Simulation of Fine Dust Surface Concentrations Over the Western United States by Optimizing the Particle Size Distribution
Publication TypeJournal Article
Year of Publication2013
JournalGeophysical Research Letters
Number12
Pages3270-3275
Date Published05/2013
Abstract / Summary

To improve estimates of remote contributions of dust to fine particulate matter (PM2.5) in the western United States, new dust particle size distributions (PSDs) based upon scale-invariant fragmentation theory (Kok_PSD) with constraints from in situ measurements (IMP_PSD) are implemented in a chemical transport model (GEOS-Chem). Compared to initial simulations, this leads to reductions in the mass of emitted dust particles with radii <1.8mm by 40%–60%. Consequently, the root-mean-square error in simulated fine dust concentrations compared to springtime surface observations in the western United States is reduced by 67%–81%. The ratio of simulated fine to coarse PM mass is also improved, which is not achievable by reductions in total dust emissions. The IMP_PSD best represents the PSD of dust transported from remote sources and reduces modeled PM2.5 concentrations up to 5µg/mover the western United States, which is important when considering sources contributing to nonattainment of air quality standards.

URLhttp://onlinelibrary.wiley.com/doi/10.1002/grl.50591/abstract
DOI10.1002/grl.50591
Journal: Geophysical Research Letters
Year of Publication: 2013
Number: 12
Pages: 3270-3275
Date Published: 05/2013

To improve estimates of remote contributions of dust to fine particulate matter (PM2.5) in the western United States, new dust particle size distributions (PSDs) based upon scale-invariant fragmentation theory (Kok_PSD) with constraints from in situ measurements (IMP_PSD) are implemented in a chemical transport model (GEOS-Chem). Compared to initial simulations, this leads to reductions in the mass of emitted dust particles with radii <1.8mm by 40%–60%. Consequently, the root-mean-square error in simulated fine dust concentrations compared to springtime surface observations in the western United States is reduced by 67%–81%. The ratio of simulated fine to coarse PM mass is also improved, which is not achievable by reductions in total dust emissions. The IMP_PSD best represents the PSD of dust transported from remote sources and reduces modeled PM2.5 concentrations up to 5µg/mover the western United States, which is important when considering sources contributing to nonattainment of air quality standards.

DOI: 10.1002/grl.50591
Citation:
Zhang, L, JF Kok, Q Li, and C Zhao.  2013.  "Improving Simulation of Fine Dust Surface Concentrations Over the Western United States by Optimizing the Particle Size Distribution."  Geophysical Research Letters 3270-3275.  https://doi.org/10.1002/grl.50591.