Grant: Discovery Launch Supplement

Eastern Canada have been affected recently by extreme and contrasting hydrometeorological events. In spring 2023, abnormally dry and hot conditions contributed to the worst forest fire season and short-duration heavy rainstorms in summer 2023 induced urban floods in many cities across Quebec and Nova Scotia. In agreement with the literature that predicted an intensification of the water cycle, such contrasting hydrometeorological extremes are becoming more frequent and intense. This intensification that will continue in the future is a threat to urban infrastructures and agriculture. To adapt to the changing climate, communities in Canada need to be better informed on the expected changes of the water cycle. Rainstorms that cause urban floods last few minutes up to few hours. Due to the severe underestimation of such short-duration precipitation extremes by Regional Climate Models (RCM), current climate change scenarios are inadequate to represent sub-daily precipitation changes in the future. Few years ago, the advent of Convection-Permitting RCMs (CP-RCM) using with grid meshes of a few kilometers provided a step change in improving the comprehension of the damaging weather extremes. In my Discovery program, I will use my expertise in climate and hydrological modelling to address the critical knowledge gaps that limit our ability to predict the intensification of the water cycle. Taking advantage of an emerging CP-RCM, my research program aims at advancing the understanding of the intensifying water cycle focusing on the meteorological hazards conducive to urban flooding and affecting agricultural practices over Eastern Canada. On the short-term, my research program seeks to: (1) Identify past and future changes of precipitation extremes of different durations, and (2) Project the impacts of climate change on the partitioning of rainfall at the land surface. To address these objectives, different soil moisture, evaporation, and precipitation observational datasets from classic weather stations to the more advanced satellites will be used. To investigate the future evolution of the water cycle, my research program will take advantage of the 6th generation of the Canadian Regional Climate Model (CRCM6) now capable of performing climate simulations at an unprecedented high resolution of 2.5 km, allowing to simulate more realistic storms that produce extreme weather. Then, the recent past and long-term future of the partitioning of rainfall at the land surface into interception, infiltration, and surface runoff with the CRCM6 will be analyzed. Altogether, my program will provide a specialized training environment at the interface of atmospheric sciences and hydro-engineering, as well as improving knowledge on the future evolution of the water cycle, using one of the most advanced climate model and new observations that will help the design of infrastructures that evacuate runoff from rainstorms and agronomists concerned with crop yield.