**** README FILE - GENERAL INFORMATION ****

Readme document version 20260106

---- FLUXNET DATA PRODUCT CONTENT ----

The FLUXNET data product generated by ONEFlux is an international standard used by different eddy covariance networks globally. It is a compressed archive (ZIP) that includes a set of files:

README.txt: this file, with general information about the data product

DATA_POLICY_LICENSE_AND_INSTRUCTIONS.txt: The FLUXNET data are shared under a CC-BY-4.0 data use license. See this file for details of the data license and attribution requirements when data are used.

Five files, with different time aggregations, containing the continuous data (flux and meteorological). The files (CSV following the FP Standard format) have this name structure:

    [N]_[CC-###]_FLUXNET_FLUXMET_[T]_[YS]-[YE]_[V]_[R].csv

    where:
    [N] = code identifying the source network** 
    [CC-###] = the FLUXNET site code
    [T] = the time resolution, with options HH for hourly or half-hourly, DD for daily, WW for weekly, MM for monthly, and YY for yearly
    [YS]-[YE] = the start and end years of the measurements
    [V] = the version of ONEFlux used*
    [R] = the data release version

Five files, with different time aggregations, containing the continuous variables definitions, units and information. The files (BIF Standard format) have this name structure:

    [N]_[CC-###]_FLUXNET_BIFVARINFO_[T]_[YS]-[YE]_[V]_[R].csv

    where:
    [N] = code identifying the source network** 
    [CC-###] = the FLUXNET site code
    [T] = the time resolution, with options HH for hourly or half-hourly, DD for daily, WW for weekly, MM for monthly, and YY for yearly
    [YS]-[YE] = the start and end years of the measurements
    [V] = the version of ONEFlux used*
    [R] = the data release version

Five files, with different time aggregations, containing the ERA meteorological data downscaled at the level of the site. The files (CSV following the FP Standard format) have this name structure:

    [N]_[CC-###]_FLUXNET_ERA5_[T]_[YS]-[YE]_[V]_[R].csv

    where:
    [N] = code identifying the source network** 
    [CC-###] = the FLUXNET site code
    [T] = the time resolution, with options HH for hourly or half-hourly, DD for daily, WW for weekly, MM for monthly, and YY for yearly
    [YS]-[YE] = the start and end years of the measurements
    [V] = the version of ONEFlux used*
    [R] = the data release version

One file with all the metadata and ancillary data of the site (BIF Standard format) with name structure: 

    [N]_[CC-###]_FLUXNET_BIF_[YS]-[YE]_[V]_[R].csv

    where:
    [N] = code identifying the source network** 
    [CC-###] = the FLUXNET site code
    [YS]-[YE] = the start and end years of the measurements
    [V] = the version of ONEFlux used*
    [R] = the data release version


* The version of ONEFlux included in the filename only contains the major and minor designation (e.g., v1.2) of the full code version (e.g., v1.2.1). The full ONEFlux code version can be found in the BIF metadata files.

** Regional network that prepares and manages in a coordinated and centralized way the flux/met data and the metadata for ONEFlux processing. This network is a contact for questions about the site. Explanations of the codes are available in the BADM variable PRODUCT_SOURCE_NETWORK, see BIF DATA FORMAT below.


---- CONTINUOUS DATA FORMAT AND PROCESSING ----

The continuous data are collected by each site PI and team and prepared by Regional Networks before the final processing using the ONEFlux pipeline. The processing and data format are described in Pastorello et al. 2020 and further developments of the code can be found in the ONEFlux GitHub repository (https://github.com/FLUXNET/ONEFlux).
The data are in ASCII format, comma delimited, with first row as header. Missing data are indicated as -9999 and time is expressed in local standard time (without DST). Metadata about the measurements are reported in the BIFVARINFO files.


---- BIF DATA FORMAT ----

The BIF (BADM Interchange Format, where BADM is Biological Ancillary Disturbance and Metadata) is a standard ASCII Data format to report non-continuous data (ancillary data, metadata etc.). It is described in the Table SM8 (Supplementary material) of Pastorello et al. 2020. The description of the variables is available, always updated, on the https://fluxnet.org/ website and the FLUXNET GitHub (https://github.com/FLUXNET/BIF_BADM)
An online tool to convert BIF format in tables is available at https://tinyurl.com/BIFconverter (needs Google Drive to run).


---- CONTACTS ----

For any question about the data processing and format please contact us via email at  support@fluxnet.org 


---- REFERENCE ----

Pastorello, G., Trotta, C., Canfora, E. et al. The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data. Sci Data 7, 225 (2020). https://doi.org/10.1038/s41597-020-0534-3
