Journal of Cold Regions Engineering

Lake ice and lake temperatures depend on climate and lake morphometry. Simulated lake ice and lake temperature characteristics of 10 large lakes in Minnesota were therefore related to climate parameters, geographic location, lake surface area, and depth by multiple linear regressions. The regression equations were developed because they are much easier to use than a deterministic, unsteady simulation model that requires time series of weather data as input and produces very detailed information as output. Some of the regression equations were then employed to hindcast the ice-in dates, ice-out dates, ice cover duration, and maximum ice thicknesses for several freshwater lakes in the United States and one in Canada. The hindcast results were compared with field data from the same lakes. The standard errors between observed and predicted ice-in dates, ice-out dates, ice cover duration, and maximum ice thicknesses for the lakes tested are 4 days, 6–7 days, 4–7 days, and 0.05–0.06 m, respectively, depending on the equations used. Ice-in date is slightly better predicted than ice-out date and ice cover duration. Because the 10 lakes used to develop the multiple linear regressions are all in Minnesota, and the lakes used to verify the regression equations are in Wisconsin, Maine, and Ontario, the regression equations are considered validated and applicable at least to lakes in the north-central United States and in southern Ontario.

A two-dimensional numerical model for the dynamics of surface ice transport and ice jam in rivers was developed and applied to the upper Niagara River. The model treats river ice dynamics as a two-layer system consisting of a layer of surface ice coupled with the underlying water flow. A Lagrangian discrete-parcel method was used to model the ice dynamics, and a finite-element method to model the hydrodynamics. These two components are coupled through the interaction at the interface between the ice layer and the flowing water. The model was validated using recorded data and observations of ice runs and ice jams. Subsequently, the model was used to evaluate possible measures for mitigating ice jams that adversely affect hydropower operations on the upper Niagara River.

Certrifuge model tests are used to identify the path of dyed ethylene glycol (antifreeze) when it leaks from a cylinder buried in freezing or frozen silt at different times during the freezing cycle. The paths followed are contrasted to the path followed by release of dyed water from the same cylinder in a model undergoing freezing, and in another model, to the path followed by release of the ethylene glycol from the cylinder into soil not subjected to freezing. When ethylene glycol is released after freezing has penetrated well below the elevation of the leak, it is contained, at least over that duration (simulating 0.4 years), by the surrounding ice rich frozen soil. The same behavior is observed when ethylene glycol is released into unfrozen soil that experiences no subsequent freezing. When ethylene glycol is released before freezing, subsequent freezing draws the contaminant vertically to the soil surface. When it is released as freezing is occurring at the elevation at which the ethylene glycol is released, its path is long and inclined upward, moving far from the point of injection; dyed water released at the same elevation and at the same point during the freezing process does not travel far from the point of injection before being frozen in place.