Wavelength dependence of the optical depth of multicomponent aerosols in the North of Chile

Abstract

In this work, we present the first results of measurements of UV- multi-component aerosols made by an automatic CIMEL Sunphotomer installed by NASA in Agreement with University of Tarapacá Arica? Chile. We analyze spectral measurement of t from 340-1020 nm obtained from a ground based Aerosol Robotic Network radiometers AERONET, which is located in Arica (Lat.:18° 29´S, Long.: 70° 19´ W, 25m). Desert dust aerosols are present, at this location due to the proximity of the Atacama desert (the world´s driest), and fine mode aerosols are also present. Aerosol size distribution retrieval analysis are also presented. The data show that in some days there is curvature in the ln t vs ln l plot, which is related to the dominance of the accumulation mode aerosols. In this case a second order polynomial fit to the ln τ vs ln λ provided in Arica provides a good agreement with the measurements. Satellite TOMS estimates of optical depth for this region were also obtained.