{"id":11920,"date":"2024-02-15T22:22:09","date_gmt":"2024-02-15T21:22:09","guid":{"rendered":"https:\/\/www.swissfluxnet.ethz.ch\/?page_id=11920"},"modified":"2025-07-10T13:50:51","modified_gmt":"2025-07-10T11:50:51","slug":"fluxnet-requirements-for-data-sharing","status":"publish","type":"page","link":"https:\/\/swissfluxnet.ethz.ch\/index.php\/documentation\/fluxnet-requirements-for-data-sharing\/","title":{"rendered":"FLUXNET Requirements for Data Sharing"},"content":{"rendered":"<p>Overview of required data and data format for files uploaded to <a href=\"http:\/\/gaia.agraria.unitus.it\/\" target=\"_blank\" rel=\"noopener\">EFDC<\/a> \/ <a href=\"https:\/\/fluxnet.org\/\" target=\"_blank\" rel=\"noopener\">FLUXNET<\/a> for post-processing and subsequent data sharing.<\/p>\n<p><strong>Guideline on the EFDC homepage:<\/strong><\/p>\n<ul>\n<li><a href=\"http:\/\/gaia.agraria.unitus.it\/home\/guidelines\/how-to-submit-data\/general-information\">Data submission &#8211; General Information<\/a><\/li>\n<li><a href=\"http:\/\/gaia.agraria.unitus.it\/home\/guidelines\/obtaining-data\/variables-and-formats\">Variables and formats available<\/a><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h1>Which data do we upload to FLUXNET \/ EFDC?<\/h1>\n<ul>\n<li>We upload the adjusted <code>*_fluxnet_*<\/code> output file from EddyPro (Level-1 flux calculations, for an overview of the different flux levels see here: <a href=\"https:\/\/www.swissfluxnet.ethz.ch\/index.php\/data\/ecosystem-fluxes\/flux-processing-chain\/\">Flux Processing Chain<\/a>). The EddyPro <code>*_fluxnet_*<\/code> file still has to be adjusted following the <a href=\"http:\/\/gaia.agraria.unitus.it\/home\/guidelines\/how-to-submit-data\/general-information\" target=\"_blank\" rel=\"noopener noreferrer\">EFDC guidelines<\/a> (note the required timestamp and variable names with _1_1_1, also only upload most relevant flux variables from this file, not all of them).<del><\/del><\/li>\n<li>Despite its name, the EddyPro <code>*_fluxnet_*<\/code> file cannot directly be uploaded for sharing in FLUXNET.<\/li>\n<li><strong>In some cases<\/strong>, it might be necessary to remove some clearly wrong data in the uploaded file before upload, e.g. when we are sure that a sensor was clearly defective but still produced data and erroneous fluxes were calculated. In this case, file is adjusted before upload (erroneous fluxes set to <code>-9999<\/code>).<\/li>\n<li><strong>Important: FLUXNET needs fluxes that are not oulier-removed and not u*-filtered and not gap-filled and not partitioned<\/strong> because they apply their scripts to perform all of these steps! Only when data are clearly wrong it is recommended to set the data to <code>-9999<\/code> in the data files before upload.<\/li>\n<li>In FLUXNET \/ EFDC, the understand the uploaded data as Level-2 data. In our case, we can directly upload our Level-1 data in most cases.\n<ul>\n<li>If the Level-1 data contains erroneous fluxes that need to be removed, those fluxes are set to -9999 before sharing with FLUXNET.<\/li>\n<li>Keep in mind that we upload our Level-1 data, although FLUXNET \/ EFDC always understands uploaded data as (their) Level-2:<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<blockquote><p>Level-2 data are original data submitted by the PI and checked\/filtered only for out-of-range values or clearly wrong data. The variables available are listed in the table here below and are provided as ASCII file with missing values reported as -9999 and timestamp indicating the end of the averaging period. The file produced has in the first line the variables codes.<br \/>\n&#8211; Source: <a href=\"http:\/\/gaia.agraria.unitus.it\/home\/guidelines\/obtaining-data\/variables-and-formats\" target=\"_blank\" rel=\"noopener noreferrer\">EFDC<\/a><\/p><\/blockquote>\n<p>&nbsp;<\/p>\n<h1>Metadata<\/h1>\n<ul>\n<li>the <strong>site FluxID<\/strong> in the form CC-SSS (two character country code, three character site identifier within country) \u2013 e.g., CH-Dav<\/li>\n<li>the <strong>latitude and longitude<\/strong> for the site in the WGS 84 decimal format with at least four decimal points resolution \u2013 e.g., 42.5378 \/ -72.1715<\/li>\n<li><strong>timezone of the site<\/strong> (time series, if timezone changed; timestamps are all local standard time, no daylight savings) \u2013 e.g., UTC-5<\/li>\n<li><strong>height<\/strong> of the gas analyser \u2013 e.g., 30.0 m<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h1>File Format<\/h1>\n<ul>\n<li>CSV file<\/li>\n<li>Missing values or error code: <code>-9999<\/code><\/li>\n<li>FLUXNET\/EFDC now needs two timestamps in the file: <code>TIMESTAMP_START<\/code> and <code>TIMESTAMP_END<\/code><\/li>\n<li>Timestamp in the format: YYYYMMDDhhmm<\/li>\n<li><strong>Yearly range needed<\/strong>: one file for each year.\n<ul>\n<li>First <code>TIMESTAMP_START<\/code> in the respective file for e.g. 2020 is <code>202001010000<\/code>, last <code>TIMESTAMP_START<\/code>&nbsp; is <code>202012312330<\/code><\/li>\n<li>First <code>TIMESTAMP_END<\/code> in the respective file for e.g. 2020 is <code>202001010030<\/code>, last <code>TIMESTAMP_END<\/code>&nbsp; is <code>202101010000<\/code><\/li>\n<\/ul>\n<\/li>\n<li>Time resolution: 30min (60min also accepted)<\/li>\n<li>Variable names need suffix, e.g. <code>_1_1_1<\/code>, <code>_1_2_1<\/code>, &#8230;<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h1>Flux Variables<\/h1>\n<p><em>from the EddyPro *full_output* file, renamed according to <a href=\"http:\/\/gaia.agraria.unitus.it\/home\/guidelines\/how-to-submit-data\/variables-codes\" target=\"_blank\" rel=\"noopener\">EFDC \/ FLUXNET variable codes<\/a><\/em><\/p>\n<h2>CO2<\/h2>\n<ul>\n<li><strong>FC <\/strong>(\u00b5molCO2 m-2 s-1): Carbon Dioxide (CO2) turbulent flux (without storage component)<\/li>\n<li><strong>FC_SSITC_TEST <\/strong>(adimensional): Quality check &#8211; CO2 flux &#8211; * see the note<\/li>\n<li><strong>SC <\/strong>(\u00b5molCO2 m-2 s-1): Carbon Dioxide (CO2) storage flux measured with a vertical profile system, optional if tower shorter than 3 m<\/li>\n<li><strong>CO2 <\/strong>(\u00b5molCO2 mol-1): Carbon Dioxide (CO2) mole fraction in moist air<\/li>\n<\/ul>\n<h2>H2O<\/h2>\n<ul>\n<li><strong>LE <\/strong>(W m-2): latent heat turbulent flux, without storage correction<\/li>\n<li><strong>LE_SSITC_TEST <\/strong>(adimensional): Quality check &#8211; latent heat flux &#8211; * see the note<\/li>\n<li><strong>SLE <\/strong>(W m-2): Latent heat storage below flux measurement level<\/li>\n<li><strong>H2O <\/strong>(ppt: mmolH2O mol-1): Water (H2O) vapor mole fraction<\/li>\n<\/ul>\n<h2>H<\/h2>\n<ul>\n<li><strong>H <\/strong>(W m-2): sensible heat turbulent flux, without storage correction<\/li>\n<li><strong>H_SSITC_TEST <\/strong>(adimensional): Quality check &#8211; sensible heat flux &#8211; * see the note<\/li>\n<li><strong>SH <\/strong>(W m-2): Heat storage in air below flux measurement level<\/li>\n<\/ul>\n<h2>Wind &amp; Footprint<\/h2>\n<ul>\n<li><strong>USTAR <\/strong>(m s-1): friction velocity<\/li>\n<li><strong>WD <\/strong>(\u00b0): wind direction<\/li>\n<li><strong>WS <\/strong>(m s-1): horizontal wind speed<\/li>\n<li><strong>FETCH_70 <\/strong>(m): Fetch at which footprint cumulated probability is 70%<\/li>\n<li><strong>FETCH_90 <\/strong>(m): Fetch at which footprint cumulated probability is 90%<\/li>\n<li><strong>FETCH_MAX <\/strong>(m): Fetch at which footprint cumulated probability is maximum<\/li>\n<\/ul>\n<p>* note: for the quality flag definition please refer to this document: <a href=\"http:\/\/gaia.agraria.unitus.it\/Quality_flags_definition.pdf\" target=\"_blank\" rel=\"noopener\">Quality Flags Definition<\/a><\/p>\n<p>&nbsp;<\/p>\n<h1>Meteo Variables<\/h1>\n<p><em>from meteo data files, renamed according to <a href=\"http:\/\/gaia.agraria.unitus.it\/home\/guidelines\/how-to-submit-data\/variables-codes\" target=\"_blank\" rel=\"noopener\">EFDC \/ FLUXNET variable codes<\/a><\/em><\/p>\n<ul>\n<li><b>G<\/b> (W m-2): ground heat flux, needed for the energy balance closure calculations<\/li>\n<li><b>LW_IN<\/b> (W m-2): incoming (down-welling) longwave radiation<\/li>\n<li><strong>LW_OUT<\/strong> (W m-2): outgoing longwave radiation<\/li>\n<li><b>NETRAD<\/b> (W m-2): net radiation, needed for the energy balance closure calculations<\/li>\n<li><b>P<\/b> (mm): precipitation total of each 30 or 60 minute period<\/li>\n<li><b>PA<\/b> (kPa): atmospheric pressure<\/li>\n<li><b>PPFD_IN<\/b> (\u00b5molPhotons m-2 s-1): incoming photosynthetic photon flux density<\/li>\n<li><b>PPFD_OUT<\/b> (\u00b5molPhotons m-2 s-1): outgoing photosynthetic photon flux density<\/li>\n<li><b>RH<\/b> (%): relative humidity (range 0\u2013100%)<\/li>\n<li><b>SW_IN<\/b> (W m-2): incoming shortwave radiation<\/li>\n<li><strong>SW_OUT<\/strong> (W m-2): outgoing shortwave radiation<\/li>\n<li><b>SWC<\/b> (%): soil water content (volumetric), range 0\u2013100%<\/li>\n<li><b>TA <\/b>(\u00b0C): air temperature<\/li>\n<li><b>TS<\/b> (\u00b0C): soil temperature<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h1>Example: FLUXNET Processing Steps<\/h1>\n<p>The processing steps in FLUXNET are approximately like this:<\/p>\n<ol>\n<li>Level-1 fluxes are uploaded by PI<\/li>\n<li>Level-3 produced by FLUXNET\n<ol>\n<li>calculation of NEE (storage correction, gives NEE, <a href=\"https:\/\/www.biogeosciences.net\/3\/571\/2006\/\" target=\"_blank\" rel=\"noopener noreferrer\">Papale et al., 2006<\/a>)<\/li>\n<li>extension of QC flags, quality checks (spikes, <a href=\"https:\/\/www.bgc-jena.mpg.de\/5624872\/Ustar-filtering\" target=\"_blank\" rel=\"noopener noreferrer\">u* filtering<\/a> flags to filter for low-turbulence conditions, creates additional data gaps)<\/li>\n<\/ol>\n<\/li>\n<li>Level-4 produced by FLUXNET\n<ol>\n<li>application of QC flags, e.g. spike removal (<a href=\"https:\/\/www.biogeosciences.net\/3\/571\/2006\/\" target=\"_blank\" rel=\"noopener noreferrer\">Papale et al., 2006<\/a>)<\/li>\n<li><a href=\"https:\/\/www.bgc-jena.mpg.de\/5624860\/Gap-filling\" target=\"_blank\" rel=\"noopener noreferrer\">gap-filling<\/a><\/li>\n<li><a href=\"https:\/\/www.bgc-jena.mpg.de\/5624848\/Flux-partitioning\" target=\"_blank\" rel=\"noopener noreferrer\">partitioning<\/a> (using NEE: Gross Primary Production, GPP; Terrestrial Ecosystem Respiration, TER)<\/li>\n<li>aggregation to different time resolutions<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview of required data and data format for files uploaded to EFDC \/ FLUXNET for post-processing and subsequent data sharing. Guideline on the EFDC homepage: Data submission &#8211; General Information Variables and formats available &nbsp; Which data do we upload to FLUXNET \/ EFDC? We upload the adjusted *_fluxnet_* output . . . <a class=\"readmore-link\" href=\"https:\/\/swissfluxnet.ethz.ch\/index.php\/documentation\/fluxnet-requirements-for-data-sharing\/\">Read more<\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"parent":11817,"menu_order":18,"comment_status":"closed","ping_status":"closed","template":"template-full-width.php","meta":{"_acf_changed":false,"_lmt_disableupdate":"no","_lmt_disable":"no","ngg_post_thumbnail":0,"footnotes":""},"coauthors":[314],"class_list":["post-11920","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/pages\/11920","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/comments?post=11920"}],"version-history":[{"count":8,"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/pages\/11920\/revisions"}],"predecessor-version":[{"id":13125,"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/pages\/11920\/revisions\/13125"}],"up":[{"embeddable":true,"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/pages\/11817"}],"wp:attachment":[{"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/media?parent=11920"}],"wp:term":[{"taxonomy":"author","embeddable":true,"href":"https:\/\/swissfluxnet.ethz.ch\/index.php\/wp-json\/wp\/v2\/coauthors?post=11920"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}