computeSunsetHourDoy: computeSunsetHourDoy

In solartime: Utilities Dealing with Solar Time Such as Sun Position and Time of Sunrise

Description

Compute the hour of sunrise for given day and coordinates

Usage

computeSunsetHourDoy(doy, latDeg, longDeg = NA, 
    timeZone = NA, isCorrectSolartime = TRUE)

Arguments

doy	integer vector with day of year [DoY, 1..366]
latDeg	Latitude in (decimal) degrees
longDeg	Longitude in (decimal) degrees (not required if solar time is sufficient)
timeZone	Time zone (in hours) ahead of UTC (Central Europe is +1) (not required if solar time is sufficient)
isCorrectSolartime	sunrise hour is computed first for solar time (where noon is exactly at 12:00) If TRUE (default) then sunrise hour is converted to local winter time, based on timeZone and longitude.

Value

numeric vector of length(doy) giving the time of sunset in hours after midnight. Polar night is indicated by 12h, polar day by 24h.

Author(s)

Thomas Wutzler

Examples

today <-
  as.POSIXlt(Sys.Date())$yday
(sunset <- computeSunsetHourDoy(today, latDeg = 51, isCorrectSolartime = FALSE))
(sunset <- computeSunsetHourDoy(today, latDeg = 51, longDeg = 11.586, timeZone = +1))
#
doy <- 1:366
plot( computeSunsetHourDoy(doy, latDeg = 51, isCorrectSolartime = FALSE) ~ doy )
# north pole: daylength 0 and 24 hours
plot( computeSunsetHourDoy( doy, latDeg = +80, isCorrectSolartime = FALSE) ~ doy )
plot( computeSunsetHourDoy( doy, latDeg = -80, isCorrectSolartime = FALSE) ~ doy )

solartime documentation built on April 22, 2021, 5:10 p.m.