Determining Adequate Representation of Worst-Case Pollutant Concentrations from Aircraft Emissions using the Emissions and Dispersion Modeling System(EDMS Version 4.11)

摘要

When conducting dispersion analyses,the U.S.Environmental Protection Agency recommends that multiple years of hourly weather data be applied to computer modeling to make sure that the worst-cast meteorological conditions are adequately represented in the modeling results.This recommendation is based on a study completed 20 years ago,prior to the development of modern air quality dispersion models.The Emissions and Dispersion Modeling System(EDMS)is an air quality dispersion model required by the Federal Aviation Administration for use in estimating dispersion of aircraft emissions for the purpose of preparing an Environmental Impact Statement.This research examined four case studies where five consecutive years of site-specific weather data were applied in the EDMS for the purpose of estimating pollutant concentrations of aircraft emissions for comparison and analysis.The case studies represented hypothetical airports located within unique climatological regions of the United States.The results of the research showed the year-to-year changes in the one-hour concentrations of carbon moNO_xide within the various climate regions and recommendations were made regarding the necessity of applying multiple years of weather data for dispersion analyses of aircraft emissions.This issue is particularly relevant considering that hourly computer calculations of pollutant concentrations are prohibitively expensive and excessively time consuming.