| Autor: |
Wei Li, Yuxuan Wang, Xueying Liu, Soleimanian, Ehsan, Griggs, Travis, Flynn, James, Walter, Paul |
| Zdroj: |
Atmospheric Chemistry & Physics Discussions; 6/16/2023, p1-21, 21p |
| Abstrakt: |
Mechanisms for high offshore ozone (O3) events in the Houston area have not been systematically examined due to limited O3 measurements over water. In this study, we used the datasets collected by three boats deployed in Galveston Bay and the Gulf of Mexico during the Tracking Aerosol Convection Interactions ExpeRiment/Air Quality (TRACER-AQ) field campaign period (September 2021) in combination with the Weather Research and Forecasting (WRF) coupled Comprehensive Air quality Model with Extensions (CAMx) modeling system (WRF-CAMx) to investigate the reasons for high offshore O3. The model can capture the spatiotemporal variability of daytime (10:00-18:00) O3 for the three boats (R > 0.7) but tends to overestimate O3 by ~10 ppb on clean days and underestimate O3 by ~3 ppb during high-O3 events. The process analysis tool in CAMx identifies O3 chemistry as the major process leading to high O3 concentrations. The region-wide increase of long-lived VOCs through advection not only leads to more O3 production under a NOx-limited regime but also fosters VOC-limited O3 formation along western Galveston Bay and the Gulf coast under high-NOx conditions brought by the northeasterly winds from the Houston Ship Channel. Two case studies illustrate that high offshore O3 events can develop under both large- and meso-scale circulations, indicating both the regional and local emissions need to be stringently controlled. Wind conditions are demonstrated to be important meteorological factors in such events, so they must be well represented in photochemical models to forecast air quality over the urban coastal regions accurately. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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