AERMOD Results using Standard and Mesoscale Model Meteorological Data

摘要

This study reviews AERMOD-predicted concentrations for several hypothetical sources at locations throughout the United States. An analysis of the differences in the meteorological parameters affecting dispersion, including wind speed and direction and mixing heights, contained in AERMOD-ready data sets to the data resource (i.e., NWS observations or WRF output processed through MMIF in various manners) is presented. Also presented is an analysis of the sensitivity of AERMOD-predicted concentrations to the meteorological data source and processing methodology. A second review focuses on the sensitivity of modeled concentrations to the choice of WRF grid point, representing a typical airport location and a typical application site, for each region included in the analysis. These analyses show that considerable variation can be seen in all meteorological parameters generated by MMIF and AERMET depending on the source of raw data (WRF versus NWS data) and the valid location of the meteorological data when using MMIF (location representative of airport versus application site). Variations in planetary boundary layer parameters, such as mixing height, can also occur depending on the options used to generated AERMOD-ready data in MMIF. These variations in meteorological parameters can lead to considerable differences in AERMOD predicated concentrations as shown through a series of case studies using hypothetical sources. Users of MMIF should be familiar with the assumptions that are made when generating AERMOD-ready meteorological data and the sensitivity of the various inputs and analysis methodologies that can be used to when using data generated by this tool.