Daniel Orozco Sanchez¹, Dairo Alegria Campo¹, Sonia Gaona Jurado¹, Alvaro Efrain Bastidas¹

1.Universidad del Cauca Popayan - Colombia

Colombian southwest region is characterized by an important mountain system: The Andes, characterized by volcanoes of important activity, vast tropical forests and its nearness to Amazonic region and Pacific Ocean. In this region, there are located the cities of Popayán (Cauca Department), Cali (Valle del Cauca Department) and Pasto (Department Of Nariño). In the Valle´s Department and in the Northern part of Cauca´s Department there is an important industrial zone, mainly related to the sugar cane production. Previous to cane harvest, crops are burned to facilitate its manual cut; in addition, in the process of obtaining the sugar, remainders of the cane are used as fuel. The burning of this biomass, along with the gas discharges of vehicles with gasoline motors and diesel engine, gas discharge of volcanic origin, and biogenic tropical forest contamination are the main atmospheric contamination sources, which are damaging air quality, cultivations, and human health in the region. In addition, this low pressure zone is where the greater ozone production takes place and where the contamination interchange between the Northern and the southern part of America happens. This paper shows the classification and characterization of atmospheric aerosols in Popayán Colombia, using sunphotometer data of aerosol optical thickness (AOT), and Angstrom alpha parameter, parameters that allow us to study and to classify the aerosols in the study zone. The analysis of the scatter diagram between AOT and alpha is a habitual procedure to identify types of aerosols according to the region.