Evaluation of air quality models for the simulation of a high ozone episode in the Houston metropolitan area

摘要: Abstract A high ozone event in the Houston–Galveston–Brazoria area was utilized to study shortcomings of current air quality models. To improve baseline simulations with Comprehensive Air Model Extensions (CAMx) for developing state implementation plan, Texas Commission on Environmental Quality (TCEQ) imputed emissions highly reactive volatile organic compounds (HRVOCs) by scaling amount fugitive olefins co-emitted NOx from selected point sources, effectively multiplying 3–12 times over regular inventory values. In this paper, CAMx and Community Multiscale (CMAQ) model were used determine if HRVOC consistent observed atmospheric conditions. With base emissions, CMAQ both Carbon-Bond 4 (CB-4) mechanism simulated similar concentrations. But predicted lower peaks than vicinity downwind Ship Channel other HRVOC-rich areas. Based analyses sensitivity different emission inputs vertical diffusion algorithms model, we found that modeled atmosphere lacked reactivity produce event. Although improved prediction at surface sites, but ethylene concentrations not measurements super sites (La Porte Clinton) NOAA aircraft. Several tests designed provide additional radicals into system research results suggested lack may need be corrected targeted, probably episodic, increase sources Houston Channel. Additional investigation production efficiency chemical mechanisms is necessary pinpoint uncertainty issues.