Evaporation and Sensible Heat Exchange for a Shallow Lake

Latent and sensible heat fluxes are dependent upon the depth of a water body and increase with decreasing depth. The intensification of the energy and mass exchange between a shallow basin and the atmosphere is caused mainly by changes in the thermal regime of the shallow water basin as well as the aerodynamic roughness of its surface. Presented in the paper is a model approach based on the bulk formulation for the deep sea and an additional correction term for shallow water. Two different models for deep sea exchange were tested, first, a bulk equation model with additional stability and roughness functions and second, a three layer model with molecular, buffer, and turbulent layers. The model results were compared to experimental data obtained during the LITFASS-98 experiment with eddy covariance techniques over a shallow lake. The comparison between the modelled (both models) and experimentally determined results is very good, with discrepancies found only for wind directions when the flux measurements were disturbed by internal boundary layers from the shores.