Analysis of spectrum variations in different seasons in composite climate zone of India

This Paper presents the study about the seasonal variations in SUN spectrum under composite climate zone of India through estimation of Average Photon Energy (APE) as quality indicator of the spectrum. Annually the APE varied form 1.81 eV to 1.98 eV. The values of APE varied between 1.88 eV to 1.9 eV during summer, 1.90 eV to 1.98 eV during monsoon and 1.81 eV to1.86 eV during winter seasons respectively. The APE for the standard AM1.5 spectrum is 1.878 eV.