nightmares (version 0.0.2)

ETo56_miss: Determination of ETo with missing data

Description

This function is used to the estimation of monthly ETo with the FAO Penman-Montheith equation for a data set containing only maximum and minimum air temperature. Please, see the example 20 from the FAO Irrigation and drainage paper 56.

Usage

ETo56_miss(lat, z, doy, tmax, tmin, tdew, u2, Rs, P)

Arguments

lat

Latitude in decimal degrees.

z

Elevation above sea level in meters.

doy

Day of the year.

tmax

Maximum air temperature in Celsius degrees.

tmin

Minimum air temperature in Celsius degrees.

tdew

Dewpoint temperature in Celsius degrees.

u2

Wind speed at 2 m height in m s-1.

Rs

Solar radiation in MJ/sq.m/day.

P

Atmospheric pressure in kPa.

Value

Reference Evapotranspiration in mm day-1

References

Allen et al., 1998. Crop Evapotranspiration. Guidelines for computing crop water requirements. FAO Irrigation and drainage paper 56. http://www.fao.org/3/X0490E/x0490e00.htm.

Examples

# NOT RUN {
ETo56_miss(45.72, 200, 196, 26.6, 14.8, 14.8, 2, 22.29, 98.96)

# }