A decade of rain-on-snow detection in the Canadian Arctic: Insights from Remote Sensing and Inuit Knowledge

Rain-on-snow (ROS) events are increasing across the Arctic as the region warms, altering snow microstructure, creating ice crusts, and impacting wildlife and surface conditions. To better document these events, we combine high-resolution passive microwave data, in situ measurements, climate reanalysis, and Inuit knowledge to assess ROS variability across the Canadian Arctic Archipelago from 1987–2019. Using both fixed and variable winter windows, and validating with meteorological stations, we detect a rise in absolute ROS occurrence, especially along coastal regions. A focused analysis on Banks Island shows significantly greater ROS-affected areas in the fall, with coastal zones experiencing the highest frequency. We find that atmospheric rivers and declining autumn sea ice both contribute to increased ROS occurrence and intensity. By integrating remote sensing with Inuit observations, we improve large-scale ROS detection and understanding of their ecological consequences, particularly for Peary caribou and the communities dependent on them.