Simulation of Lake Heat Fluxes by the Canadian Small Lake Model: Offline Performance Assessment for Future Coupling with a Regional Climate Model

English Abstract:

Lakes strongly influence local and regional climate especially in regions where they are abundant. Development of a lake model for the purpose of integration within a regional climate model is therefore a subject of scientific interest. Of particular importance are the heat flux predictions provided by the lake model since they function as key forcings in a fully coupled atmosphere-land-lake system. The first step to a coupled model, is to validate and characterize the accuracy of the lake model over a range of conditions and to identify limitations. In this work, validation results from offline tests of the Canadian Small Lake Model; a deterministic, computationally efficient, 1D integral model, are presented. Sensible and latent heat fluxes simulated by the model are compared with in situ eddy covariance (EC) observations from Landing Lake (NWT, Canada) for the 2007-2009 period. Agreement between the EC data and simulated heat fluxes is assessed in terms of atmospheric stability, closure fraction and model formulation. Minimal model error appears to occur for unstable atmospheric conditions. Theses results demonstrate the ability of the 1-D lake model to reproduce both diurnal and seasonal variations in heat fluxes and surface temperatures for the open water period.