Instantaneous radiation
Added by María Suárez Muñoz 10 months ago
Hi,
I'm new with CDO and I'm looking for the best way to do some arithmetic calculations.
I have a NetCDF4 file containing daily 24-h global radiation (RAD) and I need to calculate average instantaneous radiation as:
RADinstantaneous = RAD*24*3600/daylength
As far as I know daylength can be calculated following Allen et al., 1994 as:
daylength = (24/pi) * arccos(-tan(latitude) * tan(delta))
where delta = 0.409 * sin((0.0172*yday)-1.39)
So I'm trying to learn how to include yday and latitude in operations with CDO.
I will appreciate any help.
Thank you,
María
Replies (2)
RE: Instantaneous radiation - Added by Ralf Mueller 10 months ago
hi Maria!
currently there is no internal function to compute this directly. But I am sure it can be done based on cday(), cmonth() and cyear() using the expr operator
cheers
ralf
RE: Instantaneous radiation - Added by María Suárez Muñoz 10 months ago
Hi,
Thanks for the reply!
Not sure if cday would solve it, I'd need day of the year and I don't find such a command. I'll keep looking among the expr operator to see if there is some way around.
Cheers,
María