SNO-IFA

French monitoring network ICOS-France Atmosphère

The French program for atmospheric CO2 monitoring was initiated by G. Lambert’s research group from the Centre des Faibles Radioactivités (CFR), at the Amsterdam Island station in 1980. The National Observation Service SNO-RAMCES is labeled by INSU-CNRS since 1992, with in-situ CO2 measurements at Amsterdam Island and Mace Head in Ireland, in addition to weekly air sampling for the measurement of CO2, CH4, N2O and CO by gas chromatography. The first CO2 measuring station in mainland France was opened at the top of the Puy de Dôme in 2000, then the SNO-RAMCES was gradually developed within the framework of European projects (e.g. AEROCARB, CARBOEUROPE-IP, CHIOTTO), before participating to the European ICOS research infrastructure. The SNO ICOS-France-Atmosphere now includes 18 monitoring stations, including 11 in mainland France. Five of these stations are already labeled at European level by ICOS-ERIC, two are in the process of becoming so, while the other stations are labeled at national level. For all the stations we apply measurement protocols from the specifications established by ICOS, regularly updated by the Atmospheric Thematic Center. All the CO2 and CH4 measurements of the SNO-IFA are accessible on this AERIS site, with an annual update, and with a link established with the Carbon Portal for the stations labeled by ICOS-ERIC.

Integrated Carbon Observation System (ICOS)

The long-term monitoring of atmospheric concentrations of greenhouse gases (GHGs) in the atmosphere aims to understand the natural cycles of these gases disturbed by human activities, which are the primary cause of global warming. The main greenhouse gases CO2, CH4 and N2O have anthropogenic emissions related to the extraction and combustion of fossil fuels, and the agricultural sector, as well as natural sources and sinks. Understanding and evaluating the radiative forcing of these gases requires knowledge of the budget of their sources and sinks over the entire globe at the finest possible spatial scale, and on monthly to decadal time scales. The challenge for an atmospheric measurement network is to have a sufficiently dense and precise network to quantify the fluxes of CO2, CH4 and N2O at a spatial scale allowing to differentiate between anthropogenic, biospheric and oceanic contributions. This is currently only possible with ground networks in certain regions of the globe, including Europe where the number of stations is sufficiently dense thanks to ICOS. For regions where the densification of the ground network is not possible (oceans, tropical continents) satellites can in principle provide global coverage; however, their measurements are limited to cloudless situations and the calibration of these data is particularly difficult.

The Integrated Carbon Observing System (ICOS) was designed as the European in situ observation and information system to support science and society in their efforts to mitigate climate change. ICOS is driven by understanding the sources, sinks and cycle of greenhouse gases in the atmosphere-biosphere-hydrosphere continuum. Its mission is to harmonize European greenhouse gas observations, to provide easy access to high quality, well-documented and reproducible data, and to provide relevant products in support of policy and decision support for the society. Belgium, Finland, France, Germany, Italy, the Netherlands, Norway, Sweden and Switzerland committed themselves to this mission when the ICOS ERIC (European Research Infrastructure Consortium ) in 2015. The first five years of ICOS from 2015 to 2019 focused on setting up an operational infrastructure, and the successes achieved allowed ICOS ERIC to be included in the strategy of the European Strategy Forum on research infrastructures as a reference infrastructure (ESFRI 2016). Since entering service in 2015, the Czech Republic, Denmark, the United Kingdom, Spain and Hungary have joined ICOS, while Ireland and Greece will join in 2023.

The ICOS distributed research infrastructure provides harmonized and highly accurate measurements of greenhouse gas (GHG) fluxes, within three measurement networks (Heiskanen et al., 2021):

• in the atmosphere with continuous monitoring of atmospheric concentrations of GHGs (CO2, CH4 and N2O), and meteorological parameters
• in terrestrial ecosystems with continuous monitoring of the surface fluxes of greenhouse gases, water vapor and energy as well as carbon stocks in different compartments,
• on the surface of the oceans with carbon measurements on board oceanographic and commercial vessels, as well as offshore buoys.