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.

Examples

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