LEXPLORE PLATFORM

LéXPLORE Letters No. 20

This newsletter was generated on the 23-05-2023.

The figures below are showing data for the period 02-05-2023 to 16-05-2023.

Until today, Thetis sampled 3643 depth profiles on Lake Geneva. In this Newsletter we show 59 profiles, so just 1.62% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

Slowly but surely Lake Geneva is waking up after a rather cold spring. An episode of warm air temperatures and very little wind at the beginning of May heated up the upper water column levels to more than 15 °Celsius and 2 Kelvin above previous years. Subsequently, biological activity and oxygen production was increased around the same time.

An interlude with plenty of rainfall and stronger winds put a temporary end to that warming, but brought plenty of runoff particles into the lake, visible in the backscattering plot around May 9th. Milder conditions soon returned, continuing the warming of the upper lake levels. Interestingly, Chlorophyll A concentration is still below previous years, possibly due to windier episodes towards the middle of May, not giving the phytoplankton enough opportunities to assemble.

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 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 2023: LéXPLORE Letters, 20, https://lexplore.info/wp-content/uploads/2023/05/lexplore-letters-2023-05-23.html