Evaluation and optimization of ICOS atmosphere station data as part of the labeling process

Research output: Contribution to journalArticle


The Integrated Carbon Observation System (ICOS) is a pan-European research infrastructure which provides harmonized and high-precision scientific data on the carbon cycle and the greenhouse gas budget. All stations have to undergo a rigorous assessment before being labeled, i.e., receiving approval to join the network. In this paper, we present the labeling process for the ICOS atmosphere network through the 23 stations that were labeled between November 2017 and November 2019. We describe the labeling steps, as well as the quality controls, used to verify that the ICOS data (CO2, CH4, CO and meteorological measurements) attain the expected quality level defined within ICOS. To ensure the quality of the greenhouse gas data, three to four calibration gases and two target gases are measured: one target two to three times a day, the other gases twice a month. The data are verified on a weekly basis, and tests on the station sampling lines are performed twice a year. From these high-quality data, we conclude that regular calibrations of the CO2, CH4 and CO analyzers used here (twice a month) are important in particular for carbon monoxide (CO) due to the analyzer's variability and that reducing the number of calibration injections (from four to three) in a calibration sequence is possible, saving gas and extending the calibration gas lifespan. We also show that currently, the on-site water vapor correction test does not deliver quantitative results possibly due to environmental factors. Thus the use of a drying system is strongly recommended. Finally, the mandatory regular intake line tests are shown to be useful in detecting artifacts and leaks, as shown here via three different examples at the stations.


  • Camille Yver-kwok
  • Carole Philippon
  • Peter Bergamaschi
  • Francescopiero Calzolari
  • Huilin Chen
  • Sebastien Conil
  • Paolo Cristofanelli
  • Marc Delmotte
  • Juha Hatakka
  • Michal Heliasz
  • Ove Hermansen
  • Kateřina Komínková
  • Dagmar Kubistin
  • Nicolas Kumps
  • Olivier Laurent
  • Tuomas Laurila
  • Janne Levula
  • Matthias Lindauer
  • Morgan Lopez
  • Ivan Mammarella
  • Giovanni Manca
  • Per Marklund
  • Jean-Marc Metzger
  • Stephen M. Platt
  • Michel Ramonet
  • Leonard Rivier
  • Bert Scheeren
  • Mahesh Kumar Sha
  • Paul Smith
  • Martin Steinbacher
  • Gabriela Vítková
  • Simon Wyss
External organisations
  • University of Paris-Saclay
  • European Commission Joint Research Centre, Ispra
  • CNR Institute of Atmospheric Sciences and Climate (CNR-ISAC)
  • University of Groningen
  • Observatoire Pérenne de l'Environnement (OPE)
  • Norwegian Institute for Air Research
  • Finnish Meteorological Institute
  • Global Change Research Centre of the Czech Academy of Sciences
  • German Meteorological Service (DWD)
  • Belgian Institute for Space Aeronomy
  • University of Helsinki
  • Swedish University of Agricultural Sciences
  • University of Reunion Island
  • Laboratory for Air Pollution / Environmental Technology
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Meteorology and Atmospheric Sciences
Original languageEnglish
Pages (from-to)89-116
JournalAtmospheric Measurement Techniques
Issue number1
Publication statusPublished - 2021 Jan 5
Publication categoryResearch