Solar Declination in Radians

The function calculates solar declination, which is the angular distance of the sun north or south of the earth’s equator, based on the day of year (Campbell and Norman 1998) .

dec_angle(doy)

Arguments

doy

numeric day of year (1-366). This can be obtained from standard date via day_of_year.

Value

numeric declination angle (radians).

References

Campbell GS, Norman JM (1998). Introduction to environmental biophysics, 2nd ed. edition. Springer, New York. ISBN 0387949372.

See also

Other utility functions: airpressure_from_elev(), azimuth_angle(), day_of_year(), daylength(), solar_noon(), temperature conversions, zenith_angle()

Examples

  dec_angle(doy = 112)
#> [1] 0.2082213
  dec_angle(doy = 360)
#> [1] -0.4084355