ICOS-CH is the Swiss contribution to the Integrated Carbon Observation System Research Infrastruc-ture (ICOS RI) which entered its operational phase in 2015. Overarching goals of ICOS RI are to quantify and to understand the greenhouse gas (GHG) budget of the European continent and adjacent regions based on highly standardized measurements in the atmosphere, in terrestrial ecosystems and in the ocean, and to distribute data and data products to stakeholders and user communities. With the ICOS-CH network, i.e. ETH Zurich (National Focal Point), Empa, WSL, University of Bern, University of Basel, and MeteoSwiss, Switzerland participates in ICOS RI since its beginning in 2013.

ICOS-CH commits to maintain DAV and JFJ at Class 1 level and to extend the existing network with an urban site, in response to the scientific demand for reliable measurements of the most dynamic land cover globally, and in accordance with the ICOS RI Strategy. The Swiss contribution to ICOS RI will be coordinated within Subproject A, also responsible for communication within and beyond ICOS-CH. Site infrastructure needs to be completed (in Subprojects B and C for DAV and JFJ, respectively) and upgraded (in Subproject D for Basel (BKLI)). DAV and JFJ will be maintained at Class 1 level, and BKLI developed as Associated Site, i.e., with comprehensive variable sets, regular measurement campaigns, stringent quality requirements, fast response times should sensors need repair, and near real-time data provision to ICOS RI. This requires continuous data quality assurance and quality control by well-trained technical staff and data scientists. Overall, ICOS-CH provides a unique opportunity for scientists to contribute to outstanding research and scientific innovations based on continuous, high-precision and open-access data, a comprehensive set of measurements, and an excellent infrastructure that provides on-site validations for research related to Earth system science.