A Comparison of the Spectral Distribution of Solar Radiation in a Polluted and a Clear Air Mass

Two spectroradiometer measurements are presented to illustrate differences in the spectrum of sunlight in the 0.45–0.7 μ band. Only two spectral observations are presented, one in an apparently clean cloud-free air mass, the other under a heavily polluted air mass. Both observations were taken near Houston, Texas, on 12 November 1968 at about 1800 GMT. A 23% loss in the intensity of light is attributed to attenuation by pollution in the atmosphere.