Improving simulations of fine dust surface concentrations over the western United States by optimizing the particle size distribution. Issue 12 (17th June 2013)

• Record Type: Journal Article
• Authors: Zhang, Li; Kok, Jasper F.; Henze, Daven K.; Li, Qinbin; Zhao, Chun
• Is Part Of: Geophysical research letters. Volume 40:Issue 12(2013:Jun.)
• Page Start: 3270
• Page End: 3275
• Publication Date: 2013-06-17
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/grl.50591
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>[1] To improve estimates of remote contributions of dust to fine particulate matter (PM_2.5) 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 &lt;1.8 µm 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 PM_2.5 concentrations up to 5 µg/m³ over the western United States, which is important when considering sources contributing to nonattainment of air quality standards.</p> </abstract>