title: Modeling surface energy fluxes and thermal dynamics of a seasonally ice-covered hydroelectric reservoir.
abstract: The thermal dynamics of human created northern reservoirs (e.g., water temperatures and ice cover dynamics) influence carbon processing and air-water gas exchange. Here, we developed a process-based one-dimensional model (Snow, Ice, WAater, and Sediment: SIWAS) to simulate a full year's surface energy fluxes and thermal dynamics for a moderately large (>500km(2)) boreal hydroelectric reservoir in northern Quebec, Canada. There is a lack of climate and weather data for most of the Canadian boreal so we designed SIWAS with a minimum of inputs and with a daily time step. The modeled surface energy fluxes were consistent with six years of observations from eddy covariance measurements taken in the middle of the reservoir. The simulated water temperature profiles agreed well with observations from over 100 sites across the reservoir. The model successfully captured the observed annual trend of ice cover timing, although the model overestimated the length of ice cover period (15days). Sensitivity analysis revealed that air temperature significantly affects the ice cover duration, water and sediment temperatures, but that dissolved organic carbon concentrations have little effect on the heat fluxes, and water and sediment temperatures. We conclude that the SIWAS model is capable of simulating surface energy fluxes and thermal dynamics for boreal reservoirs in regions where high temporal resolution climate data are not available. SIWAS is suitable for integration into biogeochemical models for simulating a reservoir's carbon cycle.
authors: Department of Geography, McGill University, Montréal, QC H3A 0B9, Canada. Electronic address: weifeng.wang@mcgill.ca.
authors: Weifeng
authors: W
authors: Wang
authors: Department of Geography, McGill University, Montréal, QC H3A 0B9, Canada; Centre d'Études Nordiques, Université Laval, Québec, QC G1V 0A6, Canada.
authors: Nigel T
authors: NT
authors: Roulet
authors: Department of Natural Resource Sciences, McGill University, Ste Anne de Bellevue, Montréal, QC H9X 3V9, Canada.
authors: Ian B
authors: IB
authors: Strachan
authors: Environment Production, Hydro-Québec, Montreal, QC H2Z 1A4, Canada.
authors: Alain
authors: A
authors: Tremblay
keywords: Bowen ratio; Eastmain-1 reservoir; Eddy covariance; Latent heat; Sensible heat; Turbulent kinetic energy