Natural and forced under-ice convection

摘要

Ice is highly transparent to solar energy; therefore, the spring heating of the water begins under the ice before melting. As the water temperature near the lower edge of the ice is less than the temperature of maximum density at this depth, the heat flux launches the natural convection in the upper water layer. At the same time, the forced convection may occur in the lake. We associate the origin of forced convection with random events of ascent and dissociation of methane hydrates. Using mathematical models, we study the processes of natural and forced convection beneath the ice in a deep lake under the specific conditions of Lake Baikal. The results of numerical experiments have shown that the natural convection under the ice intensifies the process of forced convection.