Chemical characterization of atmospheric aerosols at a high-altitude mountain site: a study of source apportionment

Abstract

Abstract. The study of aerosol in high mountain regions is essential because particulate matter can play a role in altering the energy balance of high mountain regions, and aerosols can accelerate glacier melting in high mountain areas by darkening the ice surface, reducing its reflectivity (albedo). Studying aerosols in high mountain areas provides insights into long-range transport of pollutants, atmospheric dynamics, and climate change impacts. These regions can serve as valuable observatories for studying atmospheric processes. The main aim of this paper is to define the main sources of aerosol over an entire year of sampling at the Col Margherita Atmospheric Observatory (MRG 46° 22’ 0.059’’ N, 11° 47’ 30.911’’ E, 2543 m a.s.l.), a high-altitude background site in the Eastern Italian Alps. Here, we discuss the potential origins of more than one hundred chemical markers (major ions, water soluble organic compounds, trace elements, rare earth elements) using different approaches. Some diagnostic ratios were applied, but source apportionment using Positive Matrix Factorization was used to define the main inputs of PM10 collected at this high-altitude site. Moreover, a characterization of the air masses helped us to confirm the aerosol sources.