Influence of open water bodies on the generation of summertime convection over the Canadian Prairies

Monday, 15 December 2014
Deepti Joshi1, Stéphane Bélair2, Marco L Carrera2 and Sylvie Leroyer1, (1)Environment Canada Dorval, Dorval, QC, Canada, (2)Environment Canada, Dorval, QC, Canada
There are still numerous water features on the Canadian landscape that are not monitored. Specifically, there are landscape features (e.g. the prairies and Canadian shield regions of North America) that are ephemeral in nature and have a significant influence on convective storm generation and local weather patterns through turbulent exchanges of sensible and latent heat between land and the atmosphere. In this study we perform a series of numerical experiments with the GEM (Global Environmental Multiscale model) model at 2.5 km resolution to examine the sensitivity of the atmospheric boundary layer to the presence of open water bodies. At present the land-water fraction in the GEM model is specified by means of static geophysical databases which do not change annually. Uncertainty is introduced into this land-water fraction and the sensitivity of the resulting soil moisture and precipitation is quantified for a series of convective precipitation events over Alberta for the summer 2014 period.