Cooling-induced Convective Littoral Currents in Lakes: Simulation and Analysis

Abstract

Cooling of lakes through the water surface at a constant per unit area rate causes, under calm conditions, the development of a horizontal temperature gradient along the littoral slope, since water columns of different depths have different rates of temperature change. The temperature gradient gives rise to a convective circulation that consists of a cool undercurrent and an unstable surface return flow. This thermally induced circulation initiates water exchange between the littoral and pelagic regions with potential for transport of dissolved constituents, thereby affecting the water quality of the lake.