Investigation of Interaction of Sea Breeze Circulation and O3 Distribution over New York Metropolitan Area Using WRF-Chem during 2018 Long Island Sound Tropospheric Ozone Study (LISTOS)

Despite a decrease in anthropogenic emissions in the northeast U.S. over the past decades, the New York City (NYC) metropolitan area still faces episodes when summertime Ozone (O₃) exceeds the National Ambient Air Quality Standards. Complex factors, including emissions, weather conditions, transboundary transport, and local flows, make O₃ prediction challenging. This study focused on a high O₃ case with multiple O₃ peaks observed at Westport, CT on August 6, 2018, using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) model. Our analysis shows improved initial condition enhanced the simulation of sea breeze front development and the temporal variation of surface O₃. Morning O₃ surges at Westport were attributed to local photochemical production. Plumes rich in O₃ and precursor gases transported by winds from the New York City (NYC) and New jersey (NJ) accumulated over the Long Island Sound and converged over coastal CT due to the sound breeze. An Atlantic Ocean front in the early evening transported pollutants from Long Island to coastal CT. Understanding these complexities aids in formulating effective local O₃ mitigation strategies.