w: Solar time angle

Description Usage Arguments Details Note References

Description

Solar time angle at midpoint of the period (for periods < 1 day).

Usage

1
w(x, long.deg, control = list(Lz = 345))

Arguments

x

date-time object (e.g, POSIXct, POSIXlt or Date objects).

long.deg

longitude of the measurement site (degrees east of Greenwich) (for periods < 1 day)

control

list for control parameters and empirical factors (see Details)

Details

control:

Lz:
longitude of the centre of the local time zone (degrees west of Greenwich)
- 0 for Greenwich
- 345 for Germany
- 330 for Cairo (Egypt)
- 255 for Bangkok (Thailand)
- 75, 90, 105 and 120 for the Eastern, Central, Rocky Mountain and Pacific time zones (United States)

Note

eq. 31 of reference

References

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).


MeTo documentation built on May 2, 2019, 3:47 p.m.