A. What differences are there in the spectra of sunlight at the top of the atmosphere and the radiation at sea level? What do these differences indicate about the interaction of photons from the sun and the atmosphere?

B. Based on your answer to part A and the wavelengths of light involved, what kinds of molecular changes happen in the atmosphere as a result of interaction with photons from the sun?

2.5 UV Visible 10% 40% Infrared 50% 2.0 Sunlight arriving at the edge of the atmosphere Sunlight arriving at the Earth's surface 1.5 5778 K black body Radiative Flux (in Wim?inm) 1.0 0.5 UV Visible 3% 44% 0.0 Infrared 53% 1000 1250 1500 Wavelength (nm) 250 500 750 1750 2000 2250 2500