Estimation of the eddy thermal conductivity for lake Botonega

Abstract

This paper presents a part of a computer model

that is suitable for limited temperature prediction

and its application for Lake Botonega, which is

located in Istria, Croatia. The main assumption of

this study is that the heat transfer can be described

by the eddy diffusivity model to formulate the

model of the heating and cooling of a lake using a

series of water and air temperature measurements.

The coefficient of thermal diffusion, which is a

function of the lake depth, is determined using the

inverse model of eddy thermal diffusivity. The

inverse model is linearized using the finite element

approach. The model of lake thermal diffusivity

consists of a conductive part and a radiative part,

with the latter part being replaced with the heat

flux on the boundary. The model parameters are

calculated in two steps—a predictor step and a

corrector step—and the coefficient of conduction is

calculated instead of the diffusion.

The estimated parameters are intended for

inclusion in a simple three-dimensional thermal

model, which provides the lake temperature

prediction that is based on previous temperature

measurements, as demonstrated in the examples.