FAO56 (version 1.0)

ExRad: Extraterrestrial Radiation for Daily Periods (R_a)

Description

ExRad returns the value of extraterrestrial radiation [\(MJ/(m^2\times day)\)].

Usage

ExRad(d_r, omega_s, phi, delta, G_sc = 0.082)

Value

The function returns the value of extraterrestrial radiation as a numeric scalar.

Arguments

d_r

A numeric scalar that denotes the inverse relative earth-sun distance.

omega_s

A numeric scalar that denotes the sunset hour angle [rad].

phi

A numeric scalar that denotes the latitude [rad].

delta

A numeric scalar that denotes the solar declination [rad].

G_sc

A numeric scalar that denotes the solar constant = 0.0820 [\(MJ/(m^2\times min)\)].

Reference

Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. (1998). Crop evapotranspiration - Guidelines for computing crop water requirements - FAO Irrigation and drainage paper 56. Fao, Rome, 300(9), D05109.

Details

This is a function to calculate the extraterrestrial radiation.

See Also

EarSunDis, SunHA, SolDec, SolRad, CSSRad.

Examples

ExRad(d_r = 0.985, omega_s = 1.527, phi = -0.35, delta = 0.12)