Chasing plastic storms: Assessing atmospheric microplastic deposition by a ‘pulse event’ of tropical storm Fiona in Eastern Canada

Atmospheric processes and extreme weather events are pathways for the global distribution and deposition of microplastics. Despite the global prevalence of meteorological events, our understanding of atmospheric microplastic pathways and fall-out to the terrestrial, aquatic and marine environment resulting from storms and severe events is limited. In this study, we geospatially consider a unique time series of the movement of atmospheric microplastics and anthropogenic microdebris during an extreme tropical storm in Atlantic Canada. The large tropical storm Fiona was recorded as the deepest cyclone that caused the worst financial damage on record for Eastern Canada during its’ landfall in Nova Scotia (September 22^nd to 24^th 2022). We collected a unique timeseries of passive deposition samples of atmospheric fall-out before, during, and after storm Fiona. Through micro-Raman spectroscopy and Nile Red fluorescence techniques, we chemically and morphologically characterized particles and quantifies the microdebris and microplastic fallout resulting from the storm. Using back trajectory modelling we aim to identify storm related sources and movement of these particles prior to deposition. As climate change drives increased storm frequency and intensity, it becomes more critical than ever to obtain meteorological baseline data of these pathways.