Presentation
Greenhouse gas (GHG) measurements in the ICOS-France-Atmosphere SNO are carried out using cavity ring-down spectrometers (CRDS). Two types of instrument are used in the network:
- Picarro G2401 for measuring CO2, CH4 and CO
- Picarro G5310/PI5310 for measuring N2O and CO
These instruments enable fast (~1Hz) and high-precision analysis of the main GHGs. Before being installed on site, their performances are determined and validated by the ICOS-ATC team. Once on site, they are calibrated monthly on a four-cylinder scale, themselves calibrated on the international scale of the World Meteorological Organization (WMO) at our central laboratory (ETG). Data quality control and analyzer performance are ensured by the daily injection of a target gas whose mole fractions have been previously determined at the ETG.
In addition to this daily control, two sets of three cylinders are analyzed cyclically from station to station, in order to check the coherence of the network according to the criteria set by the WMO.
Data are transferred daily and processed in near-real time on a database at LSCE.
