The radiation at the earth’s surface varies widely due to
(1) Atmospheric effects, including absorption and scattering
(2) Local variations in the atmosphere, such as water vapour, clouds, and pollution
(3) Latitude of the location
(4) The season of the year and the time of day
1
1, 2 and 4
2
1, 2 and 3
3
1, 3 and 4
4
1, 2, 3 and 4