Cascading Density Currents from the Petit Lac to the Grand Lac of Lake Geneva

Hydrodynamics and water quality of lakes are often interdependent and generally dominated by (thermal) stratification. The resulting stability of the water column strongly limits vertical exchange of tracers such as heat, dissolved oxygen or nutrients.

Density currents generated by differential cooling in lakes with shallow shore regions or side basins are associated with increased vertical mixing, deep water renewal and cross-shore transport of nutrients and other substances.

Combining field experiments and 3D numerical modeling, we can assess the overall significance of cold-water density currents generated by differential cooling during wintertime in Lake Geneva for the energy balance of the lake as well as their contribution to deep water renewal.

A key aspect of the project is the interbasin exchange between the two main basins of Lake Geneva, the shallow Petit Lac and the deep Grand Lac.

This project is supported by the Swiss National Science Foundation (SNF).

Contact: Dr Rafael Reiss, postdoctoral fellow

EPFL News article (September 24, 2021):
Deepwater renewal in Lake Geneva in light of climate change