LEXPLORE PLATFORM

LéXPLORE Letters No. 64

This newsletter was generated on the 21-03-2025.

The figures below are showing data for the period 07-01-2025 to 21-01-2025.

Until today, Thetis sampled 4906 depth profiles on Lake Geneva. In this Newsletter we show 22 profiles, so just 0.45% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

Thetis is back from its winter slumber. We can identify first records for 2025 starting on January 16th. As expected, at this time of the year, the vertical temperature gradient in the water column is extremely weak, with temperatures between 7.8 and 7.7 degree Celcius. The same is true for the oxygen and chlorophyll distribution.

Compared to the few Thetis measurements from previous years, the water temperature anomalies highlight slighly colder values for this year.

Shortly before the start of the Thetis measurements, we see a episode of freezing atmospheric conditions, probably contributing to the negative water temperature anomalies.

What is displayed

Data from the Thetis profiler:

  • Water Temperature in °Celsius

  • Water Temperature Anomaly on daily resolution with respect to to the available daily climatology from Thetis so far in Kelvin

  • Dissolved Oxygen mg/L

  • Oxygen Saturation in %

  • Chlorophyll A in μg/L

  • Chlorophyll A Anomaly on daily resolution with respect to to the available daily climatology from Thetis so far in μg/L

  • Backscattering of light 700 nm in 1.e-2 m-1, representing zooplankton or larger particles in the water

Data from the automatic weather station:

  • Air Temperature in °Celsius

  • Wind Speed in m/s

  • Precipitation in mm

Data from the wave buoy:

  • Wave height in decimeter

Authorship and further information

This newsletter is created by EPFL, specifically Martin Wegmann.

For more information about LéXPLORE, contacting us and possibilities to visit the platform: lexplore.info

If you want to know more about the Chlorophyll distribution across Lake Geneva, have a look at the satellite data map by our colleagues at CIPEL.

If you want to know more about the water temperature distribution across Lake Geneva, have a look at the lake reanalysis and forecasts by our colleagues at EAWAG.

If you want to use figures from the LéXPLORE Letters, you can use the following citation:

EPFL, Limnology Center 2025: LéXPLORE Letters, 64, https://lexplore.info/wp-content/uploads/2025/03/lexplore-letters-2025-03-21.html