LEXPLORE PLATFORM

LéXPLORE Letters No. 2

This newsletter was generated on the 13-09-2022.

The figures below are showing data for the period 23-08-2022 to 06-09-2022.

Until today, Thetis sampled 2883 depth profiles on Lake Geneva. In this Newsletter we show 40 profiles, so just 0.01% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

These two late summer weeks show very stable environmental conditions. With clear sky, no storms and textbook daily air temperature amplitudes, the lake is quite stratified. The upper lake levels still show large positive temperature anomalies, meaning the lake is still “too warm” for the season we are in.

With the increased nutrient input from previous weeks and the high temperature and solar radiation inputs from this period, the phytoplankton abundance is increasing between 10 and 20 meters depth. This dynamic is also visible in the oxygen availability. Confirmed by field samples on the platform and with the absence of runoff events, the backscattering of light at 700 nm shows high abundance of, most possibly, zooplankton feeding on the phytoplankton in the calm lake conditions.

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

  • Backscattering of light 700 nm in 1.e-2 m-1, representing zooplankton or larger particles in the water

  • Salinity in mg/L

Data from the automatic weather station:

  • Air Temperature in °Celsius

  • Wind Speend in m/s

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, 2, https://lexplore.info/wp-content/uploads/2022/09/lexplore-letters-2022-09-13.html