Lake-river-atmosphere Interactions as Simulated by the Canadian Regional Climate Model (CRCM5) over North-east Canada

Abstract:

Lakes are important components of the climate system and can affect regional climate by modulating surface albedo, surface energy and moisture budgets, especially for the lake rich regions such as Canada. From the regional hydrology perspective, interactions between lakes and rivers are important as streamflow patterns can be significantly modified by lake storage, while lake levels can be modified by streamflows. In this study, using a suite of experiments performed with the fifth generation of the Canadian Regional Climate Model (CRCM5), we try to assess the interactions between lakes and rivers and their impact on the atmosphere, over north-east Canada; in these simulations lakes are represented by the Hostetler model, while rivers are modelled using the modified WATROUTE scheme, including interflow. Comparison of CRCM5 simulations with and without lakes suggests big differences in winter/summer precipitation and winter temperature. CRCM5 simulations performed with and without lake-river interactions suggest improved representation of streamflows when lake storage is taken into account. Introduction of interflow shows some streamflow increases during summer and fall seasons, for majority of the rivers, and some impacts on the land atmosphere interactions via modified soil moisture.