LEXPLORE PLATFORM

LéXPLORE Letters No. 16

This newsletter was generated on the 28-03-2023.

The figures below are showing data for the period 07-03-2023 to 21-03-2023.

Until today, Thetis sampled 3430 depth profiles on Lake Geneva. In this Newsletter we show 52 profiles, so just 1.52% of the recorded data. The complete data set is available at Datalakes.

Data highlights of this issue

With winter being over and temperatures rising, we see a slow return of biological activity and oxygen production in the upper lake levels. Nevertheless, water temperature and Chlorophyll A anomalies are still very much negative, highlighting that the water column below our platform was warmer in previous March months. Within these previously recorded data is the very sunny and warm spring of 2020, which definitely impacts the magnitude and sign of our anomalies here.

We also finally see some well needed precipitation recorded by the platform, together with extremely high wave heights of above 1 meter! One of the highest wave heights ever measured by us at this location. The genesis of these waves is most likely connected to a storm front passing through, since we can see a strong drop of air temperatures after the maxima in wind speed. This represents a canonical pattern of warm and cold sectors of storm fronts passing by.

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, 16, https://lexplore.info/wp-content/uploads/2023/03/lexplore-letters-2023-03-28.html