SIPCO2: Quantification of Lake Geneva biological metabolism and validation of novel pCO2 sensor system

This project focuses on the development and validation of SIPCO2, a low-cost and accessible sensor designed to measure high-frequency CO₂ (pCO₂) dynamics in freshwater systems. Built using readily available materials, SIPCO2 provides an affordable alternative to commercial sensors and enables continuous monitoring of CO₂ exchanges between lakes and the atmosphere. After initial successful deployments in small lakes in the United States, the system was tested at the LéXPLORE platform to evaluate its performance in a large lake environment.

Measurements collected in Lake Geneva revealed strong short-term variability in surface water pCO₂, with values ranging from near atmospheric equilibrium to significant undersaturation. These results indicate rapid shifts between net CO₂ production and uptake, and show that CO₂ dynamics do not always follow expected day–night (diel) cycles. Ongoing analyses will compare SIPCO2 data with other sensors and environmental measurements to better understand the processes driving this variability and to validate the system’s accuracy.

Julian M. Jacobs, student in Environmental biology, Hamilton (USA)