Extending the Atmospheric River Concept to Aerosols: Climate and Air Quality Impacts

(ARs) construct to analyze aerosol atmospheric rivers(AARs) and consider their impacts. More specifically, our study is the first to develop anobjective global algorithm for detecting AARs, develop a climatology of AARs, show theircontributions to major global aerosol transport pathways, and illustrate how AAR events candrive extreme cases of poor air quality conditions. Our methodology and analysis separatelyaccount for dust (DU), carbonaceous (CA, accounting for organic and black carbon separatelywhere appropriate), sea salt (SS) and sulfate (SU) aerosols. For each of these aerosol species,there are long-range regional transport pathways with AARs accounting for a sizable fraction(40-80%) of the annual total transport in relatively few events (20-40 AAR days/year). Theclimatological results show that DU AARs mostly originate from desert areas, SS AARs aremostly present over the oceanic regions, whereas CA AARs are more frequent over theNorthern Hemisphere and often extend from tropical forests. This study also highlights theimportance of the source-receptor relationships between the emission sources and AARdrivenair quality impacts over the receptor regions. Examples include a CA AAR over SouthAmerica that impacted visibility and air quality over São Paulo as well as a recent DU AARover the tropical Atlantic, the so-called “Godzilla” dust storm, that increased the aerosoloptical thickness measured at an AERONET station in Tallahassee, Florida from 0.2 to 1.4.