27AtChem Evaluation of a WRF-Chem-HYSPLIT modeling framework to simulate smoke-taint conditions in the western US.

The presence of volatile phenol (VP) in the atmosphere can negatively influence human health and the environment. VPs can also accumulate in grapes causing detrimental effects for the wine industry. The primary source of high concentrations of VPs in wine comes from smoke contamination from wildfires, commonly known as smoke taint. These compounds can impart smoky, ashy flavors to wines, affecting their quality and marketability. This phenomenon has impacted wineries in the western US during the past decade as wildfire frequency has increased. In this study, we investigate the capabilities of an air quality modeling framework to provide information on two wildfire events in 2018 and 2020 at a winery in central WA. A couple of chemical mechanisms within the WRF-Chem model are used to investigate their abilities to simulate the behavior of VP in the troposphere, including their sources, chemical reactions, transport, and fate during conditions with and without smoke taint. Additionally, we performed back trajectory simulations using the HYSPLIT model to identify the sources, pathways, and travel time of the air parcels that arrive at the wineries. Combining the outputs of the chemical transport model and the results from the back trajectory analysis, we characterize the photochemical aging of smoke plumes and identify the fate of VP along the trajectories and at the wineries. The insights gained from this research could help vineyard managers and winemakers mitigate the effects of smoke taint, improving wine quality and industry resilience in the face of increasing wildfire events.