Author(s): Yonas Dibike; Terry Prowse; Tuomo Saloranta; Roxanne Ahmed
Linked Author(s):
Keywords: No Keywords
Abstract: Freshwater ice plays an important role in physical, geochemical and biological processes in coldregions lakes. The formation and breakup of ice are, therefore, important seasonal events in midto high-latitude cold regions. There is increasing concern regarding how climate change and variability will affect lake-water thermal structure and lake-ice characteristics, particularly ice formation, duration, breakup, thickness and composition. This study employs a one-dimensional process-based multi-year lake ice model, MyLake, to simulate the evolution of the Northern Hemisphere lake-ice and thermal structure patterns under a changing climate. After testing thehypothetical lakes positioned at 2.5olatitude and longitude resolution. For the baseline period of1960 to 1999, the lake-ice model was driven by gridded atmospheric forcings from ERA-40global reanalysis data set while atmospheric model forcings corresponding to future (2040–2079) climate were prepared by modifying the ERA-40 data according to the Canadian Global Climate Model (CGCM3) projection based on the SRES A2 emissions scenario. Analysis of the modelling results indicate that the future warming will result in an overall increase in lake-water temperature, with summer stratification starting earlier and extending later into the year. The timing of freeze-up is projected to be delayed by 5 to 20 days and break-up advanced by approximately 10 to 30 days, thereby resulting in an overall decrease of lake-ice duration by about 15 to 50 days. Maximum lake-ice thickness will also be reduced by 10 to 50 cm. The change in maximum snow depth on the lake-ice ranges between-20 to+10 cm, while the change in white-ice thickness range between-20 to+5 cm depending on the geographic location and other climate parameters.
Year: 2010