LEXPLORE PLATFORM

LéXPLORE Letters No. 58

This newsletter was generated on the 05-11-2024.

The figures below are showing data for the period 15-10-2024 to 29-10-2024.

Until today, Thetis sampled 4732 depth profiles on Lake Geneva. In this Newsletter we show 44 profiles, so just 0.93% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

Thetis is fully back online, allowing us to investigate the water dynamics under the platform. Slowly entering the cold season in Switzerland, temperature gradients between the lake surface and bottom layers are more and more reduced. The high atmospheric pressure situation over Switzerland is envoking calm winds, fog generation and close to no waves.

Water temperature anomalies highlight negative values in the upper lake levels and positive values below 25 meters. Strong vertical mixing in previous months together with rather cold atmospheric temperatures in October led to this exceptional surface signal. That earlier mixing also shuffled heat energy into deeper layers, where it persists for several weeks to months. This results in even weaker vertical temperature gradients than usually for this season, possible enhancing mixing of the lake in the upcoming cold season months.

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 2024: LéXPLORE Letters, 58, https://lexplore.info/wp-content/uploads/2024/11/lexplore-letters-2024-11-05.html