LEXPLORE PLATFORM

LéXPLORE Letters No. 26

This newsletter was generated on the 15-08-2023.

The figures below are showing data for the period 25-07-2023 to 08-08-2023.

Until today, Thetis sampled 3799 depth profiles on Lake Geneva. In this Newsletter we show 25 profiles, so just 0.66% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

This issue marks the 1 Year Anniversary of the LéXPLORE Letters! Thanks for sticking around through the development of this format and we hope to bring you many more LéXPLORE Letters in the future!

The most striking feature in this issue are the water temperature anomalies, which feature colder than usual temperatures close to the lake surface as well as warmer than usual temperatures below 15 meters depth. The puzzling temperature distribution can be explained when looking at our wind and wave sensors. Very windy episodes at the end of July and going into August shook up and turned over the water column, redistributing heat and nutrients. The fresh nutrients from deeper levels also fueled the positive Chlorophyll A anomalies around August 2nd.

Maximum daily air temperatures of around 20 °Celsius left many of us wondering if summer is already gone. A low pressure weather system over the North Sea was responsible for this rather unusual summer storm episode in Central Europe.

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 2023: LéXPLORE Letters, 26, https://lexplore.info/wp-content/uploads/2023/08/lexplore-letters-2023-08-15.html