HEAT FLUX IN LAKE MENDOTA1

Abstract

The physical processes of heat transfer at the lake’s surface and the internal heat flux are studied for ‘“average” Lake Mendota and for 1958–59. The surface heat budget is determined quantitatively. Details of the internal fluxes of the heat supplied or lost at the surface are discussed, with emphasis on the effects of wind stirring and hydrostatic stability. It is shown that a well‐known solution to Fourier’s heat conduction equation suffices to describe many of the features of the internal temperature range and heat flux when an effective thermal diffusivity is introduced.The solution is further used to demonstrate that the internal seiche along the thermocline causing heat flow in bottom sediments may account for 40% of the heat transfer to the hypolimnion.