et_0: The FAO Penman-Monteith crop reference evapotranspiration

In alexdum/climatetools: Tools and Data for Weather and Climate Analysis

The FAO Penman-Monteith crop reference evapotranspiration

Description

The panel of experts recommended in May 1990 the adoption of the FAO Penman-Monteith combination method as a new standard for reference evapotranspiration and advised on procedures for calculation of the various parameters (http://www.fao.org/docrep/X0490E/x0490e06.htm)

Usage

et_0(
  Alt,
  Lat,
  Dates,
  Tavg = NA,
  Tmax,
  Tmin,
  Rh = NA,
  RHmax = NA,
  RHmin = NA,
  Sd = NA,
  Rs = NA,
  Ws,
  Rads = F
)

Arguments

Alt	station altitude (m)
Lat	latitude in degrees (WGS84; EPSG:4326)
Dates	date field reprezenting days of measurements
Tavg	daily mean temperature (ºC)
Tmax	daily maximum temperature (ºC)
Tmin	daily minimum temperature (ºC)
Rh	daily mean relative humidity (%)
RHmax	daily maximum relative humidity (%)
RHmin	daily minimum relative humidity (%)
Sd	daily sunshine duration (hours)
Rs	daily global solar radiation (MJ m-2 day-1)
Ws	daily wind speed (m/s) at 2m above ground level
Rads	if is TRUE return shortwave and longwave radiation

References

http://www.fao.org/docrep/X0490E/x0490e08.htm

Examples

data(buc_baneasa)
# convert wind speed form 10 magl to 2 magl
ws2m <- wind_log(buc_baneasa$Ws,10, 0.1, 2)
# compute ET0
et <- et_0( Alt = 90, Lat = 44.51072, Dates = as.Date(buc_baneasa$Date),
Tmax = buc_baneasa$Tmax, Tmin = buc_baneasa$Tmax, Rh = buc_baneasa$Rh,
Sd = buc_baneasa$Sd, Ws = ws2m)
plot(buc_baneasa$Date, buc_baneasa$Sd, type = "l")

alexdum/climatetools documentation built on Sept. 6, 2022, 9:12 a.m.