Short Intro
CH4 is the second most important anthropogenically emitted greenhouse gas after CO2. Its mole fraction has increased from around 722 ppb in pre-industrial times to 1824 ppb in 2013 and the anthropogenic fraction is estimated to be 60 % of the total emissions. A promising approach to improve the understanding of the CH4 budget is the use of isotopologues to distinguish between various CH4 source processes.
Our group uses state-of-the-art QCLAS to continuously monitor 12CH4, 13CH4 and CH3D, and the respective isotope ratios δ13C-CH4 and δD-CH4. Within an ongoing project, we have realized a field-deployable, autonomous platform by coupling a compact QCLAS spectrometer to a preconcentration unit, called TRace gas EXtractor (TREX). This unit enhances CH4 mole fractions by a factor of up to 500 above ambient levels and quantitatively separates interfering trace gases such as N2O and CO2 (Eyer et al. 2014, Eyer et al., 2016).

To learn more about ongoing projects please click here.

Real-time analysis of δ13C- and δD-CH4 in ambient air with laser spectroscopy