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

The Integrated Carbon Observation System (ICOS) is a pan-European research infrastructure which provides harmonized and high precision scientific data on carbon cycle and 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 atmospheric network through the 23 stations that have been 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 (greenhouse gas and meteorological measurements) attain the expected quality level defined within ICOS. To ensure the quality of the data, three to four calibration gases and two target gases, one measured two to three times a day, the other with the calibration gases (twice a month) are measured. The data are controlled on a weekly basis and tests on the station sampling lines are performed twice a year. From these high-quality data, we can conclude that regular calibrations (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 and permits saving gas and extend the calibration gas lifespan. We also show that currently, the on-site water vapor correction test does not deliver quantitative results. The use of a drying system is strongly recommended. Finally, the mandatory regular intake line tests are shown to be useful to detect artifacts and leaks as shown through shown here via three different examples at the stations.

YVER C.;  PHILIPPON Carole;  BERGAMASCHI Peter;  BIERMANN Tobias;  CALZOLARI Francescopiero;  CHEN Huilin;  CONIL Sebastien;  CRISTOFANELLI Paolo;  DELMOTTE Marc;  HATAKKA Juha;  HELIASZ Michal;  HERMANSEN Ove;  KOMÍNKOVÁ Katerina;  KUBISTIN Dagmar;  KUMPS Nicolas;  LAURENT Olivier;  LAURILA Tuomas;  LEHNER Irene;  LEVULA Janne;  LINDAUER Matthias;  LOPEZ Morgan;  MAMMARELLA Ivan;  MANCA Giovanni;  MARKLUND Per;  METZGER Jean-Marc;  MÖLDER Meelis;  PLATT Stephen M.;  RAMONET Michel;  RIVIER L.;  SCHEEREN Bert;  SHA Mahesh;  SMITH Paul;  STEINBACHER M.;  VITKOVA Gabriela;  WYSS Simon; 

2021-02-10

COPERNICUS GESELLSCHAFT MBH

JRC121302

1867-1381 (online),   

https://amt.copernicus.org/articles/14/89/2021/,    https://publications.jrc.ec.europa.eu/repository/handle/JRC121302,   

10.5194/amt-14-89-2021 (online),