This book focuses on the optical properties of atmospheric aerosols, their diurnal and seasonal variations that have been observed at Kannur (11.9oN, 75.4oE, 5 m ASL). This work has been carried out with the ground based measurements by using a sun photometer. Measurement of aerosol mass loading and chemical analysis for identifying and quantifying various inorganic chemical species gives more insight to formulate a model suited for this region. The results were quite positive in climate models to study the impact of aerosols on the atmospheric radiation balance. The results of the chemical...