LEXPLORE PLATFORM

LéXPLORE Letters No. 9

This newsletter was generated on the 20-12-2022.

The figures below are showing data for the period 29-11-2022 to 13-12-2022.

Until today, Thetis sampled 3192 depth profiles on Lake Geneva. In this Newsletter we show 56 profiles, so just 1.75% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

Happy Holidays everyone! The end of the year is approaching and with that another year of our platform observing everything Lake Geneva.

In this last issue for 2022, we see the lake cooling down further and further and finally water temperature anomalies are falling below +1.5 Kelvin for the upper lake levels. With air temperatures dropping below freezing, the upper lake layer tempreatures are now close to the observed climatology. Chlorophyll A values stay rather low for this time of the year and we do not expect any major growth in this dark and cold season. Anomalies for the 12th and 13th of December are not available, since we did not record any observations for these days in previous years, but we are very happy to have more winter recordings going forward.

The atmosphere over the lake for beginning of December is cold, but not too windy. We observe one major upwelling event around the 4th of December with deeper water reaching nearly the surface of the lake. We further see quite the precipitation event on the 9th of December, yet find no sign of runoff in the backscattering data. This is due to the fact that this precipitation event contained mostly solid precipitation in the form of snow and as such runoff generation is delayed, as temperatures after the event continued to stay close to freezing.

See you in 2023!

What is displayed

Data from the Thetis profiler:

  • Water Temperature in °Celsius

  • Water Temperature Anomaly on daily esolution 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 esolution 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 Speend 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 2022: LéXPLORE Letters, 9, https://lexplore.info/wp-content/uploads/2022/12/lexplore-letters-2022-12-20.html