LEXPLORE PLATFORM

LéXPLORE Letters No. 28

This newsletter was generated on the 17-09-2023.

The figures below are showing data for the period 22-08-2023 to 05-09-2023.

Until today, Thetis sampled 3862 depth profiles on Lake Geneva. In this Newsletter we show 30 profiles, so just 0.78% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

While Switzerland experienced a very hot summer overall, we saw a drastic decrease of air temperature and overall change of weather patterns at the end of August, which impacted Lake Geneva quite a bit. We can see a reduction of surface water temperatures together with air temperatures, leading to negative temperature anomalies, especially close to the surface around August 28th and 29th.

The associated rainfall also brought with it a high amount of runoff particles, visible in the 700 nm backscattering plot. The continuously windy period together with small but steady waves on August 31st mixed up particles, heat and oxygen in the lake and made the water column more homogeneous.

At the beginning of September, the fair weather resumed and the lake warmed up again.

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, 28, https://lexplore.info/wp-content/uploads/2023/09/lexplore-letters-2023-09-17.html