en:hydro:extraterrestrial-radiation
- en
- en
Extraterrestrial solar radiation
The extraterrestrial solar radiation can be estimated from simple geometric relationships. The distance between the sun and the earth $d_{se}$ is needed. The formula for the extraterrestrial incoming radiation $S_{ext}$ reads:
$$ S_{ex} = 15.392*d_{se} * (\omega_s * sin(\phi)*sin(\delta)+cos(\phi)*cos(\delta)*sin(\omega_s))$$
The result is in $mm/day$ of water that can be evaporated with the corresponding amount of energy. $\phi$ is the latitude.
- extraterrestrial-radiation.py
from pylab import * from numpy import * def extraterrestrialradiation(latitude,J): ds=0.4093*sin(2*pi/365*J-1.405) # to be replaced by class sha=arccos(-tan(latitude)*tan(ds)) # to be replaced by class dse=1+0.033*cos(2*pi/365*J) Sext=15.392*dse*(sha*sin(latitude)*sin(ds)+cos(latitude)*cos(ds)*sin(sha)) return Sext latitude=31 J=arange(1,365,1) plot(J,extraterrestrialradiation(latitude,J)) ytext = ylabel('extraterrestrial radiation in mm/day') xtext = xlabel('Julian day') show()
/usr/www/users/uhydro/doku/data/pages/en/hydro/extraterrestrial-radiation.txt · Last modified: 2024/04/10 10:02 by 127.0.0.1