EGU22-5396, updated on 27 Mar 2022
https://doi.org/10.5194/egusphere-egu22-5396
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Eddy covariance flux measurements of methane over an urban area in the Alps

Michael Stichaner1, Thomas Karl1, Martin Graus1, Christian Lamprecht1, Ignacio Goded2, and Niels Jensen2
Michael Stichaner et al.
  • 1Department of Atmospheric and Cryospheric Sciences, Leopold-Franzens-Universität, Innsbruck, Austria
  • 2Joint Research Centre (JRC) of the european commission, Ispra, Italy

Methane is considered as the second most important contributor to radiative forcing and thus makes it the most important non-CO2 greenhouse gas originated from anthropogenic activities. The investigation of emission sources and the mitigation strategies of these is of major importance. One of several approaches quantifying methane emissions is the top-down eddy covariance flux measurement, which is used in the investigation here.

Long-term eddy covariance flux measurements of methane over urban areas can be used to constrain important urban emission sources. These include traffic, the residential, commercial and public sectors, industry, and biogenic sources. It is believed that a large fraction of methane emissions originates from fugitive emissions, but the magnitude and nature are still poorly constrained. Here we present initial results from long-term measurements at an Alpine city (Innsbruck, Austria), and compare methane fluxes with those available from other locations. We show that a statistical gap filling model allows to compare yearly top-down methane fluxes with bottom-up emission models. The temporal and spatial disaggregation of eddy covariance flux data can be used further to hunt down and identify potential urban emission sources, by combining these fluxes with additional tracer fluxes (e.g. NMVOC, NOx, CO2). An analysis of the methane fluxes referring to heating degree days and weekday/weekend effect combined with similar analysis for trace gases like NOx, provides additional clarity about the origin of the methane emissions (e.g. traffic, residential combustion).

First results from the methane flux measurements performed during the years 2020, 2021 and 2022 are presented here.

How to cite: Stichaner, M., Karl, T., Graus, M., Lamprecht, C., Goded, I., and Jensen, N.: Eddy covariance flux measurements of methane over an urban area in the Alps, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5396, https://doi.org/10.5194/egusphere-egu22-5396, 2022.