Calculate reference ET using the Hargreaves method.

Calculate reference ET using the Hargreaves method.

Usage

etr_hargreaves(tmin, tmax, tmean, lat, days, srad = NULL)

Arguments

tmin

The minimum air temperature in deg C.

tmax

The maximum air temperature in deg C.

tmean

The average air temperature in deg C.

lat

The latitude of the measurements degrees.

days

The julian day of the measurement. Can either be an integer or date object.

srad

Downwelling shortwave radiaiton in W m^-2. Defaults to NULL. If left as null, srad will be estimated using latitude and julian day.

Value

Daily reference ET in mm day^-1

Examples

etr_hargreaves(10, 15, 5, 30, 150)
#> [1] 1.952502