Parameterization of Water Transparency in Natural Water Bodies

A new parameterization is presented to describe the space and time variations of Secchi depth depending on the integral phytoplankton biomass and surface water temperature. The parameterization was verified against field data in lakes with different types of physiographic and chemical–biological characteristics—from deep oligotrophic northern regions of Lake Ladoga to shallow hypereutrophic Pskovskoe Lake. The results of verification show that the new parameterization can be used for solving a wide range of either hydrothermodynamic or hydrobiological problems. In particular, in the simulation of the thermal regime of water bodies, the proposed parameterization can be used to evaluate the coefficient of extinction of solar radiation. In the development of models to describe aquatic ecosystem functioning, the new parameterization can be used to evaluate the thickness of the trophogenic layer and phytoplankton primary production.