Fellowship project summary:

The use of remotely sensed data to detect climate change related ecosystem shifts in lakes.

Global warming affects lake ecosystems and can cause lake ecosystem shifts. Increasing water temperature intensifies the thermal stratification of deep lakes, reducing the vertical mixing intensity. Warming has, thus, the potential to shift the mixing regime of lakes. Mixing reduction can have severe implications for the entire lake ecosystem. Reduced deep water renewal hinders the vertical transport of nutrients from hypolimnion to epilimnion and can increase the extent and duration of seasonal hypoxia with consequences for the lake productivity and for its entire food web.

The spatial dimensions of remotely sensed data lack a vertical component, but horizontal gradients could help a better understanding of internal processes of lakes and the identification of lake mixing or ecosystem anomalies. Seasonal overturning, indeed, often occurs with different timing across the lake. Thus, the spatial character of remotely sensed data can reveal important processes in freshwater systems and can help assessing the long-term variability in the overturning behaviour of large lakes in the context of climate change. We aim at analysing the spatial patterns of remotely sensed lake water properties and link such patterns to documented anomalies or shifts of lake ecosystems.

Research Fellow: Elisa Calamita

Host Institution: eawag