At the 12th Conference on Air Quality Modeling, the United States Environmental Protection Agency (EPA) reviewed several development initiatives to improve the AERMOD model. These initiatives include the following areas: 1) low wind speed conditions, 2) building downwash, 3) dispersion from overwater sources, 4) NO2 modeling issues, 5) source characterization / plume rise issues, and 6) treatment of the plume behavior in convective conditions. Since 2019, there has been progress in each of these areas in terms of model formulation updates or field studies to be used to evaluate various options being considered for advances in these areas. Areas of progress are as follows: 1) Low wind speed conditions – new AERMOD model options and ongoing field studies 2) Building downwash - new AERMOD model options and ongoing field studies 3) Dispersion from overwater sources – new wind tunnel studies planned for offshore platform types 4) NO2 modeling issues - new AERMOD model options and ongoing field studies 5) Source characterization / plume rise issues – updates on field study evaluations 6) Plume behavior in convective conditions - new AERMOD model options and ongoing field studies This presentation will report on overall progress in these areas, especially with a new AERMOD release in May 2021 that incorporates many new features addressing these issues.
