Mixing is one of the fundamental pillars enabling lakes to fulfill their vital services. However, mixing doesn’t always follow textbook scenarios—especially in exceptionally deep lakes. Of Canada’s 2 million lakes, Quesnel Lake in British Columbia stands out—deep enough to defy a physics textbook’s understanding, long enough to foster a variable climate, and important enough to make one worry about a changing climate, especially as it serves as a vital fishing habitat and holds economic significance. It is surrounded by mountains that concentrate wind forces, it has three connected arms and it is unfortunately also marred by anthropogenic pollution from a recent mine spill. Ranked as the third deepest lake in North America, the lake has a maximum depth of 511 meters.
Over the past two decades, we deployed moorings equipped with thermometer chains at various locations, including its deepest point. These observations revealed a peculiar phenomenon: annual cooling of the bottom deep thermistors, indicating interactions between the lake’s deep and surface waters. But how does this mechanism work, and how might it change in a warming climate? To answer these questions, Sherif is integrating field observations with advanced physics-based modeling techniques to unravel the mechanisms driving deep ventilation in Quesnel Lake.
Upwelling is a key process in Quesnel Lake, driving temperature fluctuations in both the lake and the Quesnel River, which significantly impact salmon migration. Our research focuses on analyzing wind patterns necessary for upwelling at Quesnel Lake, taking into account its complex topography and the lake’s geometry, which is not well-represented in reanalysis models. Additionally, Amin is utilizing over a decade of data from moorings equipped with thermometer chains, Acoustic Doppler Current Profilers (ADCPs), and meteorological stations to characterize wind-driven upwelling in Quesnel Lake.
The project is a key component of the ongoing research on salmon in Quesnel Lake, funded by the British Columbia Salmon Restoration and Innovation Fund (BCSRIF) and in collaboration with the University of Northern British Columbia (UNBC) and Fisheries and Oceans Canada (DFO). The project is supervised by Dr. Bernard Laval, who has been studying the hydrodynamics of Quesnel Lake for over 20 years. Dr. Svein Vagle from Fisheries and Oceans Canada (DFO) has been a key contributor to the project since its inception, leading mooring deployments during the annual Quesnel Lake trips.
