Abstract
The fully coupled WRF/Chem (Weather Research and Forecasting/Chemistry) model is used to simulate air quality in the Mississippi Gulf coastal region at a high resolution (4 km) for a moderately severe summer ozone episode between 18 CST 7 and 18 CST 10 June 2006. The model sensitivity is studied for meteorological and gaseous criteria pollutants (O3, NO2) using three Planetary Boundary Layer (PBL) and four land surface model (LSM) schemes and comparison of model results with monitoring station observations. Results indicated that a few combinations of PBL and LSMs could reasonably produce realistic meteorological fields and that the combination of Yonsei University (YSU) PBL and NOAH LSM provides best predictions for winds, temperature, humidity and mixed layer depth in the study region for the period of study. The diurnal range in ozone concentration is better estimated by the YSU PBL in association with either 5‐layer or NOAH land surface model. The model seems to underestimate the ozone concentrations in the study domain because of underestimation of temperatures and overestimation of winds. The underestimation of NO2 by model suggests the necessity of examining the emission data in respect of its accurate representation at model resolution. Quantitative analysis for most monitoring stations indicates that the combination of YSU PBL with NOAH LSM provides the best results for various chemical species with minimum BIAS, RMSE, and high correlation values.
Highlights
Air quality in the Central Gulf Coastal region covering Mississippi, Alabama, and Louisiana in the southeast US is affected by high ozone levels during summer season
The study presents results from nested domain WRF/Chem simulations over the Mississippi Gulf coastal region with a grid resolution of 4 km for a 3-day moderately severe ozone episode in 8–11 June 2006
The simulations are conducted with an objective to evaluate the sensitivity of the air quality simulations to model meteorological fields in the online chemistry version
Summary
Air quality in the Central Gulf Coastal region covering Mississippi, Alabama, and Louisiana in the southeast US is affected by high ozone levels during summer season. Summer Ozone (one of the EPA criteria pollutants of major significance, mainly formed by the oxidation process of volatile organic compounds (VOCs) in the presence of NOx (NO and NO2) and SO2 and formation driven by the sunlight intensity) episodes are some air quality concerns as considerable number of anthropogenic and biogenic sources in this area contribute to precursors of ozone in this region. Occurrence of gulf breeze (sea-land breeze), prevailing high pressure systems over mid-south or Gulf of Mexico, westerly winds and associated meteorological processes are attributed to cause high ozone levels in this coastal region [1]. Air quality/dispersion modeling in complex geographical regions as in Mississippi Gulf coastal area requires at least an accurate representation of the meteorological fields to understand various phenomena such as transport, diffusion, transformation and removal of air pollutants.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
