Calculates reference ET0 based on the Penman-Monteith model (FAO-56 Method)

This function calculates the potential evapotranspiration rate from a reference crop canopy (ET0) in mm/d.

For these calculations the analysis by FAO is followed as laid down in the FAO publication Guidelines for computing crop water requirements - FAO Irrigation and drainage paper 56 <http://www.fao.org/docrep/X0490E/x0490e00.htm#Contents>_ solar_radiation: daily shortwave radiation

penman_monteith_reference_et0(
  doy = NULL,
  latitude = NULL,
  elevation = NULL,
  tmin = NULL,
  tmax = NULL,
  tmean = NULL,
  solar_radiation = NULL,
  wind_speed = NULL,
  rhmean = NULL,
  rhmax = NULL,
  rhmin = NULL,
  tdew = NULL,
  use_rh = TRUE
)

Author

Cathy C. Westhues cathy.jubin@uni-goettingen.de