LEXPLORE PLATFORM

LéXPLORE Letters No. 56

This newsletter was generated on the 08-10-2024.

The figures below are showing data for the period 17-09-2024 to 01-10-2024.

Until today, Thetis sampled 4668 depth profiles on Lake Geneva. In this Newsletter we show 13 profiles, so just 0.28% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

Thetis is still under heavy maintenance, but the few days of Thetis data we managed to record show us a prominent feature of this autumn: The water temperature at the lake´s surface is substantially, up to -2.5 Kelvin, colder than in previous years. We see that some of the heat energy might have been shuffled to lower lake layers, visible in the positive temperature anomalies between 20 to 50 meters depth. Reasons for this temperature distribution might be found in the strong wind forcing during the first half of September, the ending of which we still see in the wind speed time series of the automatic weather station. This wind forcing could have increased the mixing of the lake in September compared to previous years.

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, 56, https://lexplore.info/wp-content/uploads/2024/10/lexplore-letters-2024-10-08.html