LEXPLORE PLATFORM

LéXPLORE Letters No. 66

This newsletter was generated on the 22-03-2025.

The figures below are showing data for the period 05-02-2025 to 19-02-2025.

Until today, Thetis sampled 4906 depth profiles on Lake Geneva. In this Newsletter we show 28 profiles, so just 0.57% of the recorded data. The complete data set is available at Datalakes.

Feb 72025Feb 10Feb 13Feb 16Feb 19−50−40−30−20−10Feb 92025Feb 16−50−40−30−20−10Feb 72025Feb 10Feb 13Feb 16Feb 19−50−40−30−20−10Feb 72025Feb 10Feb 13Feb 16Feb 19−50−40−30−20−10Feb 72025Feb 10Feb 13Feb 16Feb 19−50−40−30−20−10Feb 92025Feb 16−50−40−30−20−10Feb 72025Feb 10Feb 13Feb 16Feb 19−50−40−30−20−10Feb 92025Feb 160246810
Wind SpeedAir TemperatureWave HeightDaily Rainfall7.47.457.57.557.67.657.7[deg C]−0.4−0.200.20.4[K]8.899.29.4[mg/L]708090100110120[%]11.522.53[μg/L]−2−1012[μg/L]0246[1.e-2 m-1]TimeTimeTimeTimeTimeTimeTimeTimeDepth [m]Depth [m]Depth [m]Depth [m]Depth [m]Depth [m]Depth [m][deg C], [mm], [m/s] & [dm]TemperatureTemp. Anomaly wrt daily climatologyDissolved OxygenOxygen SaturationChlorophyll AChl. A Anomaly wrt daily climatologyBackscattering 700 nmAir Temp., Rainfall, Wind Speed and Wave Height

Data highlights of this issue

In today´s letter, we can see nicely how a small window of fair and mild weather at the beginning of February can impact the lake ecosystem.

The episode of mild weather started around February 10th and lasted for roughly three days, in which air temperature maxima reached 9 °Celsius. This in turn warmed up the water column from the top, with temperature anomalies of +0.2 Kelvin. Phytoplankton in the water started to use this energy influx to grow and in turn to produce oxygen. The chlorophyll A anomalies paint a clear picture of that event.

Shortly after, windy and cold conditions mixed and cooled down the lake 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, 66, https://lexplore.info/wp-content/uploads/2025/03/lexplore-letters-2025-03-22.html