LAKE OXYGENATION - APPLICATION OF A ONE-BOX MODEL WITH ICE COVER

A one-box exponential model with constant coefficients is capable of giving a good description of the winter oxygen uptake of a lake not subject to freezing over. A simple modification of the model accounts well for the effects of ice cover. The modified model predicts that, all else being equal, the oxygen regimes of eutrophic lakes will tend to be affected more by ice cover than those of oligotrophic lakes; that a short period of ice cover is of no great consequence for the oxygen regime of the lake, whereas a long period of ice cover results in a disproportionately large decrease in the mean lake oxygen concentration; and that the later break-up occurs, the greater will be the effect of the ice cover on the oxygen regime of the lake.