LEXPLORE PLATFORM

LéXPLORE Letters No. 44

This newsletter was generated on the 23-04-2024.

The figures below are showing data for the period 02-04-2024 to 16-04-2024.

Until today, Thetis sampled 4235 depth profiles on Lake Geneva. In this Newsletter we show 29 profiles, so just 0.68% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

This one is a roller coaster. April weather at its finest. We can see two weeks of increasing air temperature, each one ended with a violent drop in temperature. The same signature is visible in the water temperature evolution, especially at the surface of the lake. On those days of peak air temperature, nearly reaching 22° Celsius on April 14th, we also find incredibly high positive water temperature anomalies of around +3 Kelvin. The record high April temperatures are then abruptly ended on April 16th, which is immediately visible in the temperature and chlorophyll anomalies.

Interestingly, during the very warm April temperatures, Chlorophyll A anomalies stay negative throughout the water column. Reasons for that could include a lack of nutrients as well as atmospheric forcing such as wind and rain, which can disrupt the accumulation of phytoplankton.

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, 44, https://lexplore.info/wp-content/uploads/2024/04/lexplore-letters-2024-04-23.html