Author(s): Yonas Dibike; Joshua Hartmann; Laurent De Rham
Keywords: Lake Ice; Ice Formation; Growth and Dynamics
Abstract: The annual cycle of ice cover on lakes can have significant effects on lake water temperature, its quality, and biological productivity. The one-dimensional Multi-year Lake simulation model (MyLake) was used to model lake ice cover and water temperature profiles in four lakes located in different regions of Canada. The sensitivity of model outputs to climatic drivers is examined by incrementally changing the model input forcing for temperature (by 0 to +10 oC at 1 oC interval) and precipitation (by -20% to +80% at 5% interval). Projected changes in these variables between the 1986-2005 baseline and the 2041-2060 and 2081-2100 future periods from 24 CMIP5 global climate models and two emission scenarios (RCP4.5 and RCP8.5) were superimposed on the climate sensitivity simulation outputs at each lake location. The results show a general increase in lake water temperature and the corresponding decrease in lake ice thickness and cover duration under the changing climate. The median change values of end of century, RCP8.5 scenario correspond to reduction in lake ice thicknesses and ice cover durations ranging from 10 to 50 cm and 20 to 60 days, respectively. The corresponding changes in annual maximum surface water temperature ranges from 5 to 13 oC resulting in stronger thermal stratification that lasts much longer that the baseline period.