LEXPLORE PLATFORM

LéXPLORE Letters No. 65

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

The figures below are showing data for the period 21-01-2025 to 04-02-2025.

Until today, Thetis sampled 4906 depth profiles on Lake Geneva. In this Newsletter we show 59 profiles, so just 1.2% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

The most apparent environmental signal we can observe in this issue is the drastic change from negative to positive water temperature anomalies. Even though this change is just around +0.5 Kelvin over the course of a few days, it does leave a striking image in our plots. This development is triggered by the arrival of warmer atmospheric temperatures, which occurred together with increased wind, wave and precipitation activity.

The runoff from this strong precipitation event is visible in the 700 nm backscattering plot and probably also fuels the chlorophyll A increase. After the stormy condition have passed, water temperatures, backscattering and chlorophyll levels decrease again.

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, 65, https://lexplore.info/wp-content/uploads/2025/03/lexplore-letters-2025-03-21.html