Seven technical papers in this issue of the Journal of the Air and Waste Management Association (JA&WMA) were derived from presentations made at the A&WMA Specialty Conference, Guideline on Air Quality Models: The Path Forward, held March 18-21, 2013, in Raleigh, North Carolina.
This specialty conference—the fifth in the series—has been held every two years as a technical forum to increase the scientific understanding and promote the advancement of the models and procedures that go into the “Guideline on Air Quality Models,” which is part of the rules and regulations of the U.S. Clean Air Act (40 CFR part 51, Appendix W). The conference was held in Raleigh, NC, to maximize the participation of the U.S. Environmental Protection Agency's (EPA) Air Quality Modeling Group (AQMG) and Office of Research and Development (ORD) staff who work in the Research Triangle Park area. This forum provided an opportunity for modelers from around the world to provide papers on the scientific advancements they have developed and the modeling issues they have encountered to be presented and discussed by the wide range of practitioners in the audience. One unique feature of the conference is the “Town Hall” meeting, where participants can gather and discuss modeling issues with the regulatory staff in an open, unrehearsed, and unrecorded exchange lasting almost two hours.
A total of 55 papers were presented and 167 registrants participated in the discussions. The subject matter included model evaluation studies, model validation analyses, meteorological data issues, and non-Guideline modeling approaches. Of special interest were papers and discussions on background concentration determinations, threshold wind speeds for Gaussian models, downwash calculations as a function of stack height, secondary formation of aerosols, and single source evaluations of ozone impacts. All of the topics and discussions are useful in evaluating expected changes in the “Guideline” currently scheduled for 2015. The final program and proceedings can be found online at http://www.awma.org/events-webinars/past-event-proceedings. The seven papers published in this issue represent distinct advances in the science of air quality modeling and include papers on the issues of background concentration, evaluation of NEXRAD radar precipitation data in modeling, model evaluation studies, low wind speed analysis, and new model applications to the problems of single source permitting. Of special note is the paper by John S. Irwin, a retired member of EPA's ORD. His paper, “A suggested method for dispersion model evaluation” (pp. 255–264), is a seminal work growing from long-term thought and understanding of the application of models to real-world problems. We are indebted to the authors, who prepared full papers based on their conference presentations and went through an additional round of peer review to ensure the quality of these publications. The conference was a great success and we look forward to the next “Guideline” conference.
Thank You to Our Sponsors
The conference organizers also express appreciation to TRC Environmental Corporation for its sponsorship of this special publication and to the sponsors of the conference, which included Trinity Breeze, Lakes Environmental, Oris, and Met One Instruments.