PARENT SESSION
Contributed Oral Session 157: Climate Dynamics: Temperature Effects; Modeling
Friday, August 12, 8:00 AM - 11:30 AM, Meeting Room 516 D, Level 5, Palais des congrès de Montréal
Impacts of Climate Change on Permafrost Distribution in Canada in 1901-2100.
Zhang, Yu*,1, Chen, Wenjun1, Smith, Sharon2, Riseborough, Daniel2, 1 Canada Centre for Remote Sensing, Ottawa, Ontario, Canada2 Geological Survey of Canada, Ottawa, Ontario, Canada
ABSTRACT- Air temperature in northern high latitudes has increased at a higher rate than the global mean in the last century and most GCMs project that this pattern will continue. Climate warming can increase soil temperature and summer thaw depth, and induce permafrost degradation, which may alter the dynamics and functions of northern ecosystems. To address these issues, we developed a process-based model to simulate the ground thermal regimes by combining the strength of existing permafrost models and land surface process models. The temperature profile in snow and ground was simulated by solving the heat conduction equation, with the upper boundary conditions being determined using the surface energy balance, and the lower boundary conditions being defined based on the geothermal flux. The model integrated the effects of climate, vegetation, ground features and hydrological conditions based on energy and water transfer in the soil-vegetation-atmosphere system. The model was validated against measurements of energy fluxes, snow depth, soil temperature and thaw depth at four sites in Canada. We used the model to simulate the changes of permafrost distribution in Canada from 1901-2100 at 0.5-degree latitude/longitude spatial resolution. The climate data over 1901-2002 were derived from station measurements, and six climate change scenarios were selected for the period 2002-2100. The results show that climate change significantly impacted permafrost distribution and active layer thickness, and soil temperature responded to the changes in atmospheric climate in a complex way. These would directly impact hydrological, ecological and biogeochemical processes.
Key words: Permafrost, Climate change, Modeling