Evaluation of an episodic regional transport model for a multi-day sulfate episode

• Published in: Atmospheric environment 1983, Vol.17 (7), p.1225-1252
• Main Authors: Stewart, Douglas A., Morris, Ralph E., Liu, Mei-Kao, Henderson, Donald
• Format: Article
• Language: English
• Subjects: Air pollution caused by fuel industries; Applied sciences; Atmospheric pollution; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Stacks. Diffusion
• ISSN: 0004-6981
• DOI: 10.1016/0004-6981(83)90399-2

An episodic regional transport model (RTM-II) is applied to a sulfate episode that occurred over the eastern third of the United States and southeastern Canada during the latter part of July 1978. An evaluation of the model performance is presented. Measurements for regional SO 2 and sulfate concentrations obtained from up to 54 monitoring stations geographically distributed throughout the modeling region are used. Simulation results are presented in a semi-quantitative manner through region-wide isopleth diagrams and time histories at individual stations. An analysis of the residuals over all measurements, the highest 50 per cent, and highest 10 per cent of the measurements is also included. The model has a tendency to overpredict low concentrations and to underpredict high concentrations for both SO 2 and sulfate, though the effect is less pronounced for sulfate. Isopleths and time histories of sulfate predictions match observed concentrations very well though the spatial variability is not as well simulated. Correlation coefficients matched by time and location over all measurements are 0.80 for sulfate and 0.42 for SO 2.