This $2,236,536 Project Grant awarded by the National Science Foundation's Polar Programs (CFDA 47.078) will quantify the impacts of rain-on-snow (ROS) events on Arctic snowpack properties. The grant recipients, Colorado State University's Sponsored Programs division, will collect field observations, develop a snow and ice layer modeling tool (ICELAYER), and conduct outreach to evaluate how ROS events affect snow and ice characteristics relevant to wildlife like caribou and muskoxen. The 5-year project aims to produce information on the formation, thickness, location, and strength of ROS-induced ice layers within Arctic snowpacks, which are increasingly impacted by climate change. The research will involve field measurements across the Arctic and integrating the data into an enhanced snow modeling system to quantify ROS impacts on key snowpack properties over space and time.