2500, boul. de l'Université
Université de Sherbrooke
Given the currently observed warming across Canada, a correlation seems to be established with the increased occurrence of wet snow avalanches. This trend has changed over the past decade, whereas rain-on-snow events (ROS) and/or heat waves associated with liquid precipitations are more common during winter. Nowadays, global warming is influencing snow cover dynamics, and plays a crucial role in controlling precipitation patterns that leads to wet snow avalanches. Such avalanches carry heavier snow volumes and reach lower altitudes in valleys where many infrastructures are present such as roads, buildings, railways, etc.
My master's project is part of theme 3.2 of axis 3 of the CEN, which aims to assess the risks associated with environmental changes in the alpine environment. Monitoring the stability of snow in an avalanche environment is crucial for risk prevention. As a result, the goal of this project is to develop decision support tools for risk management and forecasting and to transfer these tools to different government partners. The main knowledge used is environmental monitoring, climate and numerical modelling, statistics and remote sensing.
The study site is located at Mount Fidelity in Glacier National Park, British Columbia, Canada. Mount Fidelity is closed to the public during winter. It is used as a study and monitoring site for snow since the early 1960s, when the Trans-Canada Highway was built through the Glacier National Park. The avalanche team accesses the site by snow groomer through the prepared trails. This study site is located at 1905 metres above sea level. Testing will also be done at various locations in the National Park and in the area of Golden depending on needs and local conditions during the winter season.
At the Mont Fidelity site, we have several devices such as a disdrometer. It is an instrument used to measure, among other things, the rate of fall of hydrometeors to distinguish snow, rain, hail, drizzle or sleet. Also, it allows to measure the diameter distribution of these hydrometeors to calculate the precipitation rate. Due to poor parameterization of the precipitation phase in the different models used, many biases are created, thus affecting the simulations of the snow cover stability of these mountainous regions. The SNOWPACK model used is adapted to the environment of Switzerland. Therefore, the model considers that the solid to liquid transition is at 1.2 ° C and that below this temperature the transition will be from liquid to solid, which is not representative of Canadian rockies, whose mixed precipitation can be done at much more variable temperatures.
More specifically, the goal of this project is to propose a new precipitation phase formulation in the SNOWPACK model, which will then be better adapted to Canadian conditions and which will better measure the mixed precipitation of the region. Our team has had a disdrometer installed for over 3 years at Mount Fidelity in Glacier National Park, British Columbia. This device mainly measures the rate of precipitation and the phase of it. Thus, we have an abundance of data from the region in relation to these two parameters, which will make it possible to develop a new empirical formulation of the parameterization of the phase in the SNOWPACK model. Subsequently, it will be possible to validate this new parameterization with field data, which will compare with the initial parameterization and determine the different gains obtained. To do this, simulations with the old and the new versions will be done in order to find out which is best suited to the reality of the region under study.