Our knowledge of the spatial and temporal variability of aerosols and their influence on climate is incomplete. By estimating and examining atmospheric turbidity (a convenient surrogate for the amount of aerosol in the atmospheric column), however, total aerosol load can be evaluated. My approach is to refine and apply a parameterized model for estimating monthly turbidity from readily available surface weather data and remotely sensed data, regardless of cloud cover.
Using a high-resolution spectral radiation model, instantaneous clear-sky direct irradiance is parameterized as a function of extraterrestrial irradiance, solar elevation angle, turbidity, and other parameters that represent each of the atmospheric attenuation processes. Integrating the instantaneous model over the course of the day then generates an expression for potential daily clear-sky direct irradiation. Using monthly averaged climate and satellite observations, the integrated model is solved for turbidity at selected weather station locations in the southern hemisphere. This study offers new estimates of turbidity trends and variability for terrestrial regions in the southern hemisphere