air quality

Ozone concentrations that exceed health-based National Ambient Air Quality Standards (NAAQS) constitute a significant challenge for highly populated urban areas, particularly along the coasts. In the United States (US) over 40 percent of the population reside in coastal shoreline counties despite comprising less than 10% of the land area. More specifically, urbanization creates new local climates via changes to regional surface and atmospheric properties resulting in significant impacts on the dispersion of air pollution, presenting a challenge for air quality simulations. A detailed model case study was performed targeting the unique interaction between urban meteorology and chemical transport over two coastal cities namely New York City, NY and Houston, TX. A high-resolution configuration of the Weather Research and Forecasting (WRF) model was used, where the chemistry and meteorology formulations were fully coupled using an advanced multilayer urban canopy model (uWRF – Chem). In this study, we use an airborne high-spatial-resolution ultraviolet-visible airborne spectrometer for NO2 tropospheric column data collected during the 2018 Long Island Sound Tropospheric Ozone Study (LISTOS) and the 2021 – 2022 Tracking Aerosol Convection interactions ExpeRiment (TRACER-AQ) to quantitatively evaluate the performance of uWRF-Chem model NO2 tropospheric columns over both cities. The modeling effort addresses how complex urban surfaces influence heatwaves, land-sea breezes, and PBL dynamics, and in turn, how urban and coastal meteorology affects NO2 spatial distribution and ozone generation in densely populated and industrialized cities.