Assessing Tropical Cyclone-Driven Aerosol Transport - A High-Resolution WRF-Chem Analysis of Major Hurricane Matthew...

Tropical cyclones (TCs) are traditionally viewed as atmospheric cleansers, removing pollutants through precipitation and winds. However, emerging evidence suggests that TCs also transport pollutants over long distances, with their full impact on pollutant dynamics still underexplored. In this study, aerosol transport and chemical transformation during Hurricane Matthew (2016) are analyzed using high-resolution WRF-Chem simulations. The Hurricane-Driven Aerosol Transport Analysis Framework (WHDA-TAF) is developed to assess aerosol behavior under both current and future climate scenarios. Simulations based on Pseudo Global Warming (PGW) projections indicate that aerosols, such as sea salt, particulate matter, and carbonaceous aerosols, are lifted to higher altitudes and dispersed far from the storm's core. Photochemical reactions within the cyclone generate secondary pollutants such as ozone and nitrates, which can worsen air quality even after the hurricane has dissipated. Copula-based analysis reveals that stronger hurricanes in high-emission scenarios (SSP585) are likely to increase the frequency and severity of extreme compound pollution events, even in regions distant from the storm's direct impact. These findings challenge the view of TCs as mere atmospheric cleansers, highlighting their significant role as carriers and reactors of pollutants. Enhancing model resolution is crucial to better capture such TC-aerosol interactions and address the risks of cyclone-driven aerosol transport under climate change.