Canadian Lake Ice Cover in the Early 21st-Century

Lake ice cover is a key component of the Earth’s cryosphere system. The absence of lake ice can have important implications for local energy budgets and influence the occurrence of extreme weather events, such as lake-effect snow systems. Additionally, ice formation is critical in the establishment of ice road transportation networks in areas such as Northern Canada, which allow for the transportation of goods and people during winter months. Within the WMO’s Global Climate Observing System (GCOS) Lakes Essential Climate Variable (ECV), lake ice has been identified as a key indicator for monitoring climate change. While long-term ground-based records of lake ice exist, the quantity of these measurements has declined, and over the last two decades, remote sensing has become increasingly relied on to provide information about global lake ice conditions. This is reflected in the multitude of operational lake ice products now available, including: the Multisensor Snow and Ice Mapping System (IMS), the MODIS Snow and Ice Cover, ESA Lakes CCI+ Lake Ice, and the Copernicus Land Service Lake Ice Extent products. These products exhibit different advantages and disadvantages related to the quality of retrievals, number of lakes/spatial resolution, and temporal coverage, which can limit their application for real-time monitoring or understanding of changes in lake ice conditions for smaller lakes.

This presentation will showcase a new operational product, specifically focused on providing daily lake ice coverage for lakes in Canada larger than 2.25 km². The product is adapted from the processing chain utilized for the generation of the ESA CCI+ Lake Ice Cover Product but includes data for more than 36,000 lakes (500 m grid). The product is derived from over 1.5 PB of MODIS optical data and captures variation in the ice coverage during the two most recent decades (2000 – 2023). This presentation will describe and discuss the general trends and spatial patterns in lake ice cover across Canada, with connections to recent temperature trends. Additionally, an application of the product for monitoring ice roads will be highlighted by showcasing how the resolution of the product can be used to evaluate the timing of ice cover for lakes along key identified ice routes, such as the Tibbit to Contwoyto, Wekweèti, and Gamèti winter roads.