Polar Aerosol Atmospheric Rivers: Detection, Characteristics, and Potential Applications

Aerosols play a key role in polar climate, and are affected by long-range transport from the mid-latitudes, both in the Arctic and Antarctic. This work investigates poleward extreme transport events of aerosols, referred to as polar aerosol atmospheric rivers (p-AAR), leveraging the concept of atmospheric rivers (AR) which signal extreme transport of moisture. Using reanalysis data, we build a detection catalog of p-AARs for black carbon, dust, sea salt and organic carbon aerosols, for the period 1980-2022. First, we describe the detection algorithm, discuss its sensitivity, and evaluate its validity. Then, we present several extreme transport case studies, in the Arctic and in the Antarctic, illustrating the complementarity between ARs and p-AARs. Despite similarities in transport pathways during co-occurring AR/p-AAR events, vertical profiles differ depending on the species, and large-scale transport patterns show that moisture and aerosols do not necessarily originate from the same areas. The complementarity between AR and p-AAR is also evidenced by their long-term characteristics in terms of spatial distribution, seasonality and trends. p-AAR detection, as a complement to AR, can have several important applications for better understanding polar climate and its connections to the mid-latitudes. The extreme transport of aerosol-containing air masses, from the mid-latitudes to the polar regions, can be characterized and quantified by leveraging polar Aerosol Atmospheric Rivers (p-AARs). This is similar to the Atmospheric Rivers (ARs) which carry large amounts of water to the poles and affect the overall stability of polar ecosystems. In this work, we establish a detection algorithm for p-AARs and evaluate it for different well-known aerosol intrusions or AR events. The areas most affected by p-AARs are described, their trends are investigated and we discuss the potential applications of p-AAR detection for a better understanding of polar climate. A catalog of polar aerosol atmospheric rivers (p-AAR) is provided for 1980-2022 by adapting an atmospheric river (AR) detection schemeImportant p-AAR events, representing rapid poleward transport of aerosol-enriched air masses, are presentedCombining AR and p-AAR can improve our understanding of the links between mid- and polar-latitudes, in the past, present and future climate