Aufeis formation, distribution, and dynamics are directly linked to local hydrology and ground thermal conditions that substantially vary in space and time. Knowledge of aufeis distribution and dynamics can advance our understanding of broad-scale controls on aufeis formation and inform decisions regarding potential groundwater resources, environmental assessments, and land-use planning. However, broad scale aufeis dynamics in northern Canada are not well understood beyond limited regional and sub-regional investigations, and there is high uncertainty in predicting aufeis occurrence and dynamics under a changing climate. Here we present a fully automated approach to aufeis mapping developed to overcome biases and limitations in previous semi-automated methods. Using the entire Landsat data archive, we characterize aufeis occurrence (2013 – 2023) within in a national-scale area of interest comprised by mainland portions of the Yukon, Northwest Territories, and Nunavut (AOI1), and long-term aufeis distribution and dynamics (1984 – 2025) within the Mackenzie Valley watershed (AOI2). Our aims are to demonstrate where aufeis occurrence is concentrated in northern Canada and to determine if aufeis dynamics have changed over time. Here we will present an update on our tool development, characterize how aufeis within AOI1 varies with respect to permafrost zone, surficial geology, and ecozone, and quantify trends in aufeis occurrence within AOI2 over the 42-year period.