Building a harmonised pan-European network of environmental monitoring
The quantification of CO2 sources and sinks from atmospheric measurements and eddy covariance data for estimation of CO2 budgets is rather a pan-European problem than a national or regional one. Answering this need the TACOS project aimed at establishing harmonisation of practices followed by the various laboratories belonging to the carbon cycle measurement network. This will allow better exploitation of data coming from different laboratories in different countries. Efficient and reliable CO2 monitoring will contribute significantly to reduce the adverse effects of climate change by managing the carbon cycle for conservation of carbon stocks or optimisation of carbon sequestration. The aim was to set up a source of well-characterised atmospheric air under low-pressure containers, called MELONs for other laboratories within Europe, a so-called HUB laboratory. Similarly, other HUB laboratories were planned to be developed in North America, Australia and Japan. The operational system was based on a novel high-precision analyser; LoFlo developed in Australia and on the theoretically stable air containers, the MELONs. The latter were aimed to be used for intercomparisons, but were not found stable enough for CO2 determination. Alternatively, high pressure cylinders replaced the MELONs whereby a regular filling and distribution of intercomparison samples in glass flasks was the approach followed. Intercomparison tests were conducted once on a bi-monthly basis for three years and all data coming from different laboratories including CO2 and its stable ratios, CH4 and N2O were evaluated. The programme was found successful and it is expected to be adopted by other laboratories in Australia, Japan, USA and Canada.
