I need to find the hourly sun angle (angle at which the sun strikes the Earth) for a particular position (latitude, longitude) for a given day in Belgium. I used sunAngle() from "oce" package for the 31 July 2020. t is the hourly vector starting a 00:00:00 of that day until 00:00:00 of August 1.
lat = 50.879700
long = 4.700712
t0 <- as.POSIXct(paste("2020-07-31", "00:00:00"), tz="")
t <- seq(from=t0, to=t0+86400, by="60 min")
a <- sunAngle(t, lat, long)
The result is:
a[["altitude"]]
[1] -60.225122 -49.174321 -36.305296 -22.665730 -8.661004 5.521092 19.768803
[8] 33.983602 48.017946 61.503752 72.978661 75.957727 66.875621 53.924237
[15] 40.050031 25.882692 11.628080 -2.604935 -16.717790 -30.567994 -43.875928
[22] -55.964635 -64.970966 -66.929191 -60.402859
However, this output can not be correct as it means that the sun rises at 4 am and sets at 5 pm, which is impossible for a summer day in Belgium.
Any idea of what is wrong?