Classification of Atmospheric Aerosols based on Photometric Measurements and Empirical Regional Model MUrA

Abstract

Classification of atmospheric aerosols is significant in evaluating the influence of aerosols on the climate system, identifying aerosol sources, and improving aerosol satellite retrieval algorithms. There are different ways of classifying aerosol particles, but most of them do not take into account regional characteristics. We suggest an approach to classification of main aerosol types by the spectral values of aerosol optical depth by the method of k-medians based on archival AERONET photometric observations in the Middle Urals. The spectral values of extinction coefficients calculated with the use of MOPSMAP software from data of MUrA regional aerosol model and CALIPSO global model were defined as initial centers of clusters. Five aerosol types were identified: dust, clean continental (background), polluted continental/smoke, polluted dust, and elevated smoke. The analysis of data for 2004–2012 has shown clean continental and dust aerosols to be most common in the Middle Urals (26 and 25% of observations, respectively), and the percentage of polluted continental/smoke aerosol to be 20%. The suggested approach makes it possible to determine the predominant aerosol type at an observation site, thus significantly supplementing the information received by ground-based spectral photometric measurements.