EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Methane emissions from lakes in the Alpine region: insights from two years of mobile eddy covariance flux measurements

Katharina Scholz1, Federico Carotenuto2, Beniamino Gioli2, Franco Miglietta2, Sylvie Pighini3, Ruben Sommaruga1, Enrico Tomelleri3, Giustino Tonon3, Alessandro Zaldei2, and Georg Wohlfahrt1
Katharina Scholz et al.
  • 1University of Innsbruck, Institute of Ecology, Biology, Innsbruck, Austria
  • 2Institute of Biometeorology, National Research Council, Florence, Italy
  • 3Free University of Bozen-Bolzano, Faculty of Science and Technology, Bozen, Italy

Lakes are considered an important natural source of methane (CH4). However, direct measurements of lake-atmosphere gas exchange are still sparse especially in the Alpine region. To overcome this shortcoming, we designed a mobile eddy covariance (EC) station to measure CO2, CH4, and energy fluxes at various lakes in the Alps. EC measurements were compared to flux measurements using floating chambers and related to abiotic and biotic factors like temperature, lake morphometry, dissolved components and trophic status.

During the first year, measurements were conducted at 9 lakes at different elevations ranging from 200 to 1900 m.a.s.l. to capture the spatial variability. The following year, measurements were repeated more frequently at three contrasting lakes to capture the seasonal trends of the fluxes.

The results indicate that all lakes were supersaturated with CH4. However, there was a high variability in the magnitude of CH4 emissions between lakes with generally higher emissions from warmer lakes at low elevation. In particular, the lake at the lowest elevation, Lake Caldaro, had highest dissolved CH4 concentrations and emissions and showed a clear seasonal trend with emissions peaking during the hot summer months. In contrast, the lake at the highest elevation, Lake Zoccolo, showed low CH4 concentrations and emissions with highest concentrations in fall when the water level was low.

How to cite: Scholz, K., Carotenuto, F., Gioli, B., Miglietta, F., Pighini, S., Sommaruga, R., Tomelleri, E., Tonon, G., Zaldei, A., and Wohlfahrt, G.: Methane emissions from lakes in the Alpine region: insights from two years of mobile eddy covariance flux measurements, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10020,, 2020


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