Effect of aerosols on radiation attenuation in arid environments

Abstract

Calculated values of atmospheric turbidity were computed to measure spectrally-integrated aerosol optical depth for cloudless and near cloudless days for Alice Springs, Australia and Albuquerque, New Mexico. Changes in turbidity over diurnal, seasonal and annual periods were analyzed for both arid sites. Results indicate that turbidity rarely exceeded 0.1 for either site and that the annual average value for both sites was approximately 0.05. This is in contrast to studies of turbidity in the Sahara, where background values averaging 0,5 and higher have been observed. Concerns have been raised about possible detrimental effects on global climate as a result of a high concentration of atmospheric aerosol caused by high turbidity in arid regions. The low values reported here tend to dispute the comparatively high values on which these concerns are based.