Long-term development of lakes as a result of climate change

Background

Climate change is changing our lakes. Increasing air temperatures will lead to higher temperatures in the water. In turn, lakes remain stratified for a longer period of time during Summer and Autumn, and ice cover will shorten or cease completely. These changes in the physical conditions will also affect biology and biogeochemistry. High summer temperatures can cause algae blooms. A longer stratified period leads to hypoxia in the deepwater which reduces the habitable area for fishes and can release nutrients and toxic substances such as Manganese from the sediments.

In this project, the effect of climate change on the physical processes of lakes will be investigated. Several lakes with a diverse set of boundary conditions (e. g. differing mean depth or different wind exposure) will be instrumented with logger chains. They will measure temperature and oxygen in high resolution and make it possible to resolve changes in physical conditions in response to varying climatic forcing.  In addition to direct measurements, numerical models can be used to reproduce water temperatures in lakes. Here, the empirical data obtained by the temperature chains can be used for calibration. In combination with regional climate predictions for the 21st century, these models make it possible to predict lake temperatures for possible future air temperatures according to differing greenhouse gas emission scenarios.