A Retrospective Comparison of Model-Based Forecasted PM2.5 Concentrations with Measurements

• Published in: Journal of the Air & Waste Management Association (1995) Vol. 60; no. 11; pp. 1293 - 1308
• Main Authors: Doraiswamy, Prakash, Hogrefe, Christian, Hao, Winston, Civerolo, Kevin, Ku, Jia-Yeong, Sistla, Gopal
• Format: Journal Article
• Language: English
• Published: Pittsburgh, PA Taylor & Francis Group 01.11.2010; Air & Waste Management Association
• Subjects: Air Pollutants - analysis; Applied sciences; Atmospheric pollution; Circadian Rhythm; Data Interpretation, Statistical; Databases, Factual; Environmental Monitoring; Exact sciences and technology; Forecasting; Models, Theoretical; Particle Size; Particulate Matter - analysis; Pollution; Retrospective Studies; Seasons; Concentration measurement; Atmospheric boundary layer; Morphology; Prediction; Troposphere; Air pollution; Air quality; Continuous measurement; Urban area; Pollutant emission; Modeling
• ISSN: 1096-2247; 2162-2906
• DOI: 10.3155/1047-3289.60.11.1293

This study presents an assessment of the performance of the Community Multiscale Air Quality (CMAQ) photochemical model in forecasting daily PM 2.5 (particulate matter ≤2.5 µm in aerodynamic diameter) mass concentrations over most of the eastern United States for a 2-yr period from June 14, 2006 to June 13, 2008. Model predictions were compared with filter-based and continuous measurements of PM 2.5 mass and species on a seasonal and regional basis. Results indicate an underprediction of PM 2.5 mass in spring and summer, resulting from under-predictions in sulfate and total carbon concentrations. During winter, the model overpredicted mass concentrations, mostly at the urban sites in the northeastern United States because of overpredictions in unspeciated PM 2.5 (suggesting possible overestimation of primary emissions) and sulfate. A comparison of observed and predicted diurnal profiles of PM 2.5 mass at five sites in the domain showed significant discrepancies. Sulfate diurnal profiles agreed in shape across three sites in the southern portion of the domain but differed at two sites in the northern portion of the domain. Predicted organic carbon (OC) profiles were similar in shape to mass, suggesting that discrepancies in mass profiles probably resulted from the underprediction in OC. The diurnal profiles at a highly urbanized site in New York City suggested that the over-predictions at that site might be resulting from overpredictions during the morning and evening hours, displayed as sharp peaks in predicted profiles. An examination of the predicted planetary boundary layer (PBL) heights also showed possible issues in the modeling of PBL.