LEXPLORE PLATFORM

LéXPLORE Letters No. 53

This newsletter was generated on the 28-08-2024.

The figures below are showing data for the period 07-08-2024 to 21-08-2024.

Until today, Thetis sampled 4610 depth profiles on Lake Geneva. In this Newsletter we show 45 profiles, so just 0.98% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

Thetis continues to observe very high water temperatures at the surface of the lake, while also exhibiting negative water temperature anomalies between 10 and 20 meters depth, after which anomalies are slightly positive again. A curious pattern indeed, only slightly perturbed by winds and waves, such as on the 13th and 14th of August. This event also dispersed the phytoplankton accumulation at around eight meters depth, most apparent in the dissolved oxygen plot.

A freak precipitation event was measured by the automatic weather station on August 18th, namely 70 mm per day. This amount seems borderline unrealistic, although the closest land-based weather station, operated by MeteoSwiss in Pully, recorded around 50 mm that day. This station is surrounded by hilly vineyards, which might shield the station from rainfall. In any case, a proper investigation is needed to label this recorded precipitation sum by the AWS on the platform as realistic or faulty.

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, 53, https://lexplore.info/wp-content/uploads/2024/08/lexplore-letters-2024-08-28.html