Trends and Projections for North American Lake Ice

English Abstract:

Lakes comprise a large portion of the surface cover in North America forming an important part of the cryosphere. Recent studies have demonstrated that ice break-up dates, in particular, have been occurring earlier in many parts of the Northern Hemisphere over the last 50 years in response to warmer climatic conditions in the winter and spring seasons. The timing of lake ice phenological events (e.g. break-up/freeze-up) are useful indicators of climate variability and change. The Canadian Lake Ice Model (CLIMo) was used to simulate the contemporary and future lake ice conditions for the northern hemisphere, with a focus on North America. The contemporary climate simulations were driven by both ECMWF ERA-Interim and ERA-40 reanalysis data, while the future climate simulations were driven by the Canadian Regional Climate Model (CRCM5, provided by UQAM) and the CCCma Canadian Regional Climate Model (CanRCM4: CORDEX domain Nam-22, 1951-2100) with the RCP 4.5 and 8.5 emission scenario for the future climate conditions. The simulations were run for multiple lake depths to represent both shallow and deep lakes, and with and without snow cover to represent the effects of snow redistribution over the ice surface. The 30-year mean ice break-up, freeze-up, and thickness was compared between the scenarios for Canada for 1981 – 2010 and 2071 – 2100 to examine the possible changes to the ice cover regimes. Additionally, comparisons between the simulations and available in situ data for the contemporary climate were explored at selected locations. This work will examine the preliminary results from the modelled North American lake ice dataset under present day climate and projected future conditions.