FLUXNET Requirements

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Critical metadata variables for the post-processing

  • the site FluxID in the form CC-SSS (two character country code, three character site identifier within country) – e.g., CH-Dav
  • the latitude and longitude for the site in the WGS 84 decimal format with at least four decimal points resolution – e.g., 42.5378 / -72.1715
  • timezone of the site (time series, if timezone changed; timestamps are all local standard time, no daylight savings) – e.g., UTC-5
  • height of the gas analyser – e.g., 30.0 m


Critical data variables for the post-processing, averaged or integrated over 30 or 60 minutes

Mandatory & Required

  • CO2 (µmolCO2 mol-1): Carbon Dioxide (CO2) mole fraction in moist air
  • FC (µmolCO2 m-2 s-1): Carbon Dioxide (CO2) turbulent flux (without storage component)
  • SC (µmolCO2 m-2 s-1): Carbon Dioxide (CO2) storage flux measured with a vertical profile system, optional if tower shorter than 3 m
  • H (W m-2): sensible heat turbulent flux, without storage correction
  • LE (W m-2): latent heat turbulent flux, without storage correction
  • WS (m s-1): horizontal wind speed
  • USTAR (m s-1): friction velocity
  • TA (°C): air temperature
  • RH (%): relative humidity (range 0–100%)
  • PA (kPa): atmospheric pressure
  • SW_IN (W m-2): incoming shortwave radiation

Not Mandatory

  • G (W m-2): ground heat flux, not mandatory, but needed for the energy balance closure calculations
  • NETRAD (W m-2): net radiation, not mandatory, but needed for the energy balance closure calculations
  • TS (°C): soil temperature
  • SW_IN_POT (W m-2): potential incoming shortwave radiation (top of atmosphere theoretical maximum radiation), calculated based on the site coordinates (Pastorello et al. 2019)
  • PPFD_IN (µmolPhotons m-2 s-1): incoming photosynthetic photon flux density
  • P (mm): precipitation total of each 30 or 60 minute period
  • LW_IN (W m-2): incoming (down-welling) longwave radiation
  • SWC (%): soil water content (volumetric), range 0–100%