EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

In situ measurements of greenhouse gas mole fractions over North American high-latitude regions during CoMet 2.0 Arctic mission

Michal Galkowski1, Christoph Gerbig1, Uwe Schultz1, and Andreas Fix2
Michal Galkowski et al.
  • 1Max Planck Institute for Biogeochemistry, Department of Biogeochemical Signals, Hans-Knoll Str. 10, 07745 Jena, Germany
  • 2Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany

As a second most abundant anthropogenic greenhouse gas, methane has been an object of intense study over the past years. Despite a good overall knowledge of the sources contributing to the increase of its atmospheric abundance, the precise constrain of the global methane budget remains elusive, with large uncertainties still characterizing both anthropogenic and natural emissions, especially in the regions poorly constrained by observations, such as tropical wetlands or northern high-latitude regions.

CoMet 2.0 Arctic mission, executed in August and September 2022 aimed at characterizing the distribution of CH4 and CO2 over significant regional sources with the use of a German Research Aircraft HALO (High Altitude Long-range Observatory), as well as to validate remote sensing measurements from state-of-the-art instrumentation installed on-board against a set of independent in-situ observations. These sources included both anthropogenic (oil, gas and coal industries) as well as natural sources that represent large-scale methane-emission regions (including wetlands and major deltas in the region).

We will present results of in-situ observations performed across 15 research flights performed over a variety of environments. High-precision mole fractions of CO2, CH4 and CO were measured with the the JIG (Jena In-Situ Greenhouse gas sensor, based on Picarro 2401-m) instruments, while JAS (Jena Air Sampler) allowed collection of 155 spot samples to additionally characterize N2O, H2, SF6, O2/N2, Ar/N2 and stable isotopes (not presented).

Flight strategies were adopted in order to balance the needs of different types of instrumentation aboard HALO aircraft, while simultaneously sample the atmospheric constituents in the optimal manner. These strategies included a) high- to mid-altitude horizontal legs during transfers from Base of Operations (Edmonton, Alberta) towards the specific target areas, b) local vertical profiles, c) low-altitude sections with detailed scanning of the mole fractions of atmospheric constituents across the PBL and residual layers. With the appropriate selection of strategies for targeting particular emission sources, we were able to gather a rich observation suite that demonstrates importance of interplay between regional fluxes and atmospheric dynamics on spatio-temporal ranges larger than usually considered.

How to cite: Galkowski, M., Gerbig, C., Schultz, U., and Fix, A.: In situ measurements of greenhouse gas mole fractions over North American high-latitude regions during CoMet 2.0 Arctic mission, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-14205,, 2023.