Closed chamber flux dataset comparing gas chromatography and mid-infrared laser absorption spectroscopy for greenhouse gas measurements

For the study of soil-atmosphere exchange of greenhouse gases, a commonly adopted method is to monitor the change of gas concentrations in closed chambers. The datasets presented here are raw data and subsequent flux calculation results from a study comparing two techniques to determine gas concentrations in air: Gas Chromatography (GC) and mid-infrared laser absorption spectroscopy (LAS). Both techniques were compared by carrying out simultaneous chamber measurements under field conditions on two separate days covering a range of CO2, CH4 and N2O fluxes. The GC method involved syringe sampling into gas-tight vials and subsequent laboratory analysis. In contrast to that, a LAS analyzer was directly connected to the chambers (tubing system) and thus enabled real-time, high-temporal resolution data. A detailed description of the experimental setup and the data analysis is available in Aumer & Möller et al. (2025): Technical note: Gas chromatography vs. mid-infrared laser absorption spectroscopy: A comparison of methods for measuring greenhouse gas fluxes from arable soils. EGUsphere preprint. DOI: 10.5194/egusphere-2025-2862. The long-term experiment (AKHWA project, URL: www.akhwa.de), where the experiment took place, and the laser gas analyzers were funded by the Hessian Ministry for Agriculture, Environment, Viticulture, Forestry, Hunting and Homeland Affairs (Germany).