Atmospheric Aerosol Rivers: Climate and Air Quality Impacts

Abstract:

This presentation introduces the application of the “atmospheric river” (AR) concept to aerosols as a new/alternative approach for understanding and quantifying aerosol transport extremes, hereafter “Atmospheric Aerosol Rivers” (AARs). With the motivations associated with the study of (water vapor) ARs in mind, namely their importance in helping shape Earth’s climate and accounting for an important segment of extreme weather events, this work seeks to leverage the value and success of the AR perspective for understanding, predicting and communicating the impacts of these hydrometeorology extremes (e.g. Ralph et al. 2020) to the study of aerosol transport extremes. Our presentation will highlight: 1) the development of a global AAR detection algorithm based on the Guan and Waliser (2015) AR detection algorithm, 2) its application to the MERRA-2 multi-decade aerosol reanalysis (Randles et al. 2017) that separately accounts for dust, black & organic carbon, sulphate and sea salt aerosol, 3) global descriptions of the AAR climatological features, including mean frequency and transport values, significant features of AAR temporal/spatial variability, etc, 4) AAR contributions to major large-/global-scale aerosol transport pathways and radiative forcing patterns, and 5) illustration and discussion of extreme AAR events that resulted in significant impact on local air quality.