Challenging measurement conditions on Lake Geneva this week
© 2025 EPFL Beate Anne Klepere
Researchers from the SENSE unit continued their comprehensive methane profiling campaign on Lake Geneva this week, despite challenging weather conditions that disrupted planned measurements. The fieldwork represents the second phase of a seasonal monitoring program that began in February 2025.
Led by Dr. Santona Khatun, a postdoctoral researcher who has been conducting greenhouse gas research on Lake Geneva since 2022, the team is working to understand the biogeochemical processes governing methane and nitrous oxide production, distribution, and release in Swiss lakes.
Research Team and Advanced Instrumentation
The team, led by Dr. Khatun and including EPFL R&D engineer Sebastien Lavanchy and research intern Beate Anna Klepere, continues their work with the SubOcean instrument—a sophisticated probe that enables real-time measurements of dissolved greenhouse gases with remarkable precision.
Current findings confirm that methane concentrations at the lake surface remain elevated compared to atmospheric levels, providing ongoing evidence of emissions from the water to the air. During successful deployments, the team conducts comprehensive profiling while collecting water samples for laboratory validation.
The Reality of Environmental Field Research : Challenging Weather
The week's events underscore a fundamental reality of environmental research: weather dictates the science agenda, not the other way around. August 2025 has been particularly challenging, with an average of 100mm of rain across approximately 14 days of the month and scattered thunderstorms, especially in the latter part of August as conditions turn warm.
For SENSE researchers, this means carefully planned sampling campaigns can be derailed by approaching storms, equipment deployments postponed by wind conditions, and measurement schedules rewritten by rain forecasts.
Despite these conditions, the team managed to successfully conduct measurements on Tuesday August 19th. The SubOcean probe was deployed to 300 meters depth approximately in the middle of the Lake Geneva. The team managed a 2 hours long comprehensive sampling process, including methane profiling, water sample collection, and additional environmental measurements.
However, Wednesday's planned fieldwork faced significant weather challenges. Despite early morning preparation and hopes that thunderstorms would clear by 10 AM, deteriorating conditions forced the team to return to the Léxplore platform after 40 minutes of sailing toward the measurement site.
This is the risk of the job, the weather can sometimes disrupt field work, as it was the case today.
This weather dependency is particularly challenging for research that relies on precise timing and optimal conditions. Safety protocols mandate return to shore when storms threaten, regardless of how critical the planned measurements might be for the research program.
Looking Ahead: Friday Attempt and Broader Campaign
The team plans to attempt measurements again on Friday, weather permitting, as part of their ongoing efforts to characterize methane emissions from Lake Geneva. This work forms part of a broader seasonal monitoring program aimed at capturing variations in greenhouse gas production and release throughout the year.
The research has important implications beyond Lake Geneva. The next phase of the campaign will move to Lake Cadagno from August 25-27, where the team will conduct spatial analysis using gas profiling and water sample collection in this unique alpine environment.
The ultimate goal is to determine whether Swiss alpine lakes serve as significant sources of greenhouse gases to the atmosphere, particularly during mixing seasons when stratified layers break down. Understanding the role of deep large lakes like Lake Geneva in global greenhouse gas budgets is crucial for accurate climate modeling and prediction.
The campaign continues as weather conditions permit, with researchers ready to adapt their sampling strategies to maximize data collection opportunities while ensuring safety protocols.