This is the first release of the ICOS final quality data product for eddy covariance fluxes and meteorological observations at three labelled ICOS stations in the ecosystem domain. The archives contain more detailed description of the different data files contained in the archives. Measurements have been collected using the following instructions:

ICOS Ecosystem Instructions for Air Meteorological Measurements (TA, RH, PA, WS, WD), https://doi.org/10.18160/NHEG-4KWW

ICOS Ecosystem Instructions for Turbulent Flux Measurements of CO2, Energy and Momentum, https://doi.org/10.18160/QWV4-639G

In order to simplify the use of the large number of variable produced, the Level2 data are distributed using different files that includes variables/information that are coherent and designed for specific type of users. The files have one of the three formats described above (Timeseries, BIF, or Meteo management). Here below the description of each single file produced. FLUXES: it contains the output of the eddy covariance measurements, including the quality check and filtering and the storage component. It has also the footprint information.

• File name structure: ICOSETC_CC-###_FLUXES_VP.csv (where CC-### is the official site code and VP is a two digits value that identifies the version of the processing)
• Variables description: ICOSETC_FLUXES_description.pdf
• Format: Timeseries
• Time resolution: 30 minutes
• Date coverage: from 01/01/2018 to 31/12/2018. Future versions will always start from 01/01/2018 and end 31/12 of the year before release METEOSENS: it contains the meteorological variables of each single sensors aggregated at 30 minutes time resolution.
• File name structure: ICOSETC_CC-###_METEOSENS_VP.csv (where CC-### is the official site code and VP is a two digits value that identifies the version of the processing)
• Variables description: ICOSETC_METEO_description.pdf
• Format: Timeseries
• Time resolution: 30 minutes
• Date coverage: from 01/01/2018 to 31/12/2018. Future versions will always start from 01/01/2018 and end 31/12 of the year before release METEO: it contains the meteorological variables aggregated spatially (one value per variable and vertical layer) at 30 minutes time resolution.
• File name structure: ICOSETC_CC-###_METEO_VP.csv (where CC-### is the official site code and VP is a two digits value that identifies the version of the processing)
• Variables description: ICOSETC_METEO_description.pdf
• Format: Timeseries
• Time resolution: 30 minutes
• Date coverage: from 01/01/2018 to 31/12/2018. Future versions will always start from 01/01/2018 and end 31/12 of the year before release METEOAGG: it contains the information about how the single sensor measurements are combined to obtain the spatially aggregated meteorological variables.
• File name structure: ICOSETC_CC-###_METEOAGG.csv (where CC-### is the official site code)
• Variables description: ICOSETC_METEO_description.pdf
• Format: BIF_Meteo
• Time resolution: none
• Date coverage: from 01/01/2018 to 31/12/2018. Future versions will always start from 01/01/2018 and end 31/12 of the year before release FLUXNET: it is a set of 7 files that contain fluxes and meteorological variables processed using the FLUXNET methodology (OneFlux code, like the one used for FLUXNET2015, including gapfilling and partitioning) at different time resolution (halfhourly, daily, weekly, monthly and yearly) and two additional files with auxiliary information about the processing.
• Files name structure: the five measurement files have names ICOSETC_CC-###_FLUXNET_TT_VP.csv where CC-### is the official site code, TT is the time resolution (HH, DD, WW, MM, YY) and VP is a two digits value that identifies the version of the processing. The two auxiliary files have name structures ICOSETC_CC-###_FLUXNET_AUXMETEO_VP.csv and ICOSETC_CC-###_FLUXNET_AUXNEE_VP.csv where CC-### is the official site code and VP is a two digits value that identifies the version of the processing.
• Variables description: ICOSETC_FLUXNET_description.pdf
• Format: Timeseries
• Time resolution: 30 minutes, daily, weekly, monthly, yearly
• Date coverage: from 01/01/2018 to 31/12/2018. Future versions will always start from 01/01/2018 and end 31/12 of the year before release SETUPINFO: it contains information about the model, location, maintenance and disturbances, variable measured and installation/modification date for all the sensors used in the station.
• File name structure: ICOSETC_CC-###_SETUPINFO.csv (where CC-### is the official site code)
• Variables description: ICOSETC_BIF_description.pdf
• Format: BIF
• Time resolution: sporadic
• Date coverage: from 01/01/2018 to 31/12/2018. Future versions will always start from 01/01/2018 and end 31/12 of the year before release INSTCALIB: it contains information about the calibration date for all the sensors used in the station.
• File name structure: ICOSETC_CC-###_INSTCALIB.csv (where CC-### is the official site code)
• Variables description: ICOSETC_BIF_description.pdf
• Format: BIF
• Time resolution: sporadic
• Date coverage: from 01/01/2018 to 31/12/2018. Future versions will always start from 01/01/2018 and end 31/12 of the year before release ANCILLARY: it contains all the general information and ancillary measurements collected at the station, such location, team members, species, biomass, LAI etc.
• File name structure: ICOSETC_CC-###_ANCILLARY_VP.csv (where CC-### is the official site code and VP is a two digits value that identifies the version of the processing for the variables calculated by the ETC)
• Variables description: ICOSETC_BIF_description.pdf
• Format: BIF
• Time resolution: sporadic
• Date coverage: from 01/01/2018 to 31/12/2018. Future versions will always start from 01/01/2018 and end 31/12 of the year before release