Speaker
Description
The stratification of lakes plays an important role for understanding and analysing the behaviour of lakes, as well as determining potential turning points of the system. In stably stratified lakes, the water layers can have drastically different chemical compositions, and an overturn may lead to dangerous reactions affecting the lake and surrounding environments.
Many common lake models use the potential density to compare water parcels and compute transportation effects. This approach can lead to inaccuracies, as it neglects thermobaric effects arising from the interplay between temperature and pressure. This becomes particularly apparent in deep lakes with low salinity, as density differences in deeper regions are so low that thermobaricity drives the water exchange.
The aim of this project is the incorporation of thermobaricity in commonly used lake models, as well as an analysis of thermobaric effects in model cases. In a first step, a minimal 1D model for the temperature profile of lakes is developed. This model is based on the heat equation, and an additional term is introduced to reflect the transport of heat by buoyancy-driven mixing. The resulting model is used to illustrate characteristic thermobaric effects and as a starting point for a stability analysis of the system.
