Understanding Variability in Methane Flux Measurements: Results from an Expert Survey on Chamber Flux Methods

  • Claire Treat (Speaker)
  • Katharina Jentzsch (Contributor)
  • Nicholas Nickerson (Contributor)
  • Lona van Delden (Contributor)
  • Matthias Fuchs (Contributor)
  • Baur, P. A. (Contributor)
  • Julia Boike (Contributor)
  • Jill Bubier (Contributor)
  • Jesper Christiansen (Contributor)
  • Scott J. Davidson (Contributor)
  • Bo Eberling (Contributor)
  • Glatzel, S. (Contributor)
  • Kathleen Hall (Contributor)
  • Paul J. Hanson (Contributor)
  • Nicholas Hasson (Contributor)
  • Liam Heffernan (Contributor)
  • Jacqueline Hung (Contributor)
  • Vytas Huth (Contributor)
  • Gerald Jurasinski (Contributor)
  • Sari Juutinen (Contributor)
  • Masako Kajiura (Contributor)
  • Evan Kane (Contributor)
  • Aino Korrensalo (Contributor)
  • Genevieve Noyce (Contributor)
  • Frans-Jan Parmentier (Contributor)
  • Matthias Peichl (Contributor)
  • Norbert Pirk (Contributor)
  • Maria Strack (Contributor)
  • Eeva-Stiina Tuittila (Contributor)
  • Ruth Varner (Contributor)
  • Anna Maria Virkkala (Contributor)
  • Carolina Voigt (Contributor)
  • Lei Wang (Contributor)

Activity: Talks and presentationsPoster presentationScience to Science

Description

Advances in laser spectroscopy have improved the analysis of key trace gases like CH4 and N2O, opening new possibilities through both portability and with reduced measurement times using high-frequency (>1 Hz) data. However, high-frequency and high-accuracy CH4 concentration measurements also pose challenges in the interpretation of CH4 fluxes due to non-linear behavior from earlier protocols using longer measurement times with fewer samples. Here, we used a community survey to investigate the approaches for chamber fluxes used by different researchers. We received nearly 40 responses indicating that ~75% of respondents have adopted high-frequency, multi-gas analyzers with most measurement times between 2-5 minutes. We presented a standardized set of CH4 concentrations from observed flux measurements and asked about their approach to quality control and flux calculations. We found strong agreement among the experts when CH4 fluxes exhibited linear behavior but two main approaches for non-linear fluxes. Many survey respondents discarded the initial part of the measurements due to initial disturbance related to chamber placement, while roughly the same number selected the initial part and discarded the later part of the measurements due to chamber saturation effects. Experts also strongly disagreed on the inclusion of fluxes around zero. Our study shows the need to understand drivers of the patterns visible from high-resolution analyzers and standardized procedure and guidelines for future chamber CH4 flux measurements. This is highly important to reliably quantify methane fluxes all over the world and, especially in Arctic regions where we expect the greatest changes in the near future.
Period11 Sept 2024
Event titleICOS Science Conference 2024
Event typeConference
LocationVersailles, FranceShow on map
Degree of RecognitionInternational