AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Coupled AMS and Radiocarbon Analysis of Organic Aerosols for a Yearly Cycle in Magadino
ATHANASIA VLACHOU, Kaspar Rudolf Daellenbach, Carlo Bozzetti, Francesco Canonaco, Gary Salazar, Konstantinos Agrios, Soenke Szidat, Urs Baltensperger, Imad El Haddad, Andre Prévôt, Paul Scherrer Institute
Abstract Number: 312 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Carbonaceous aerosols, which can be categorized as primary and secondary, are emitted or formed via fossil and non-fossil sources. The use of filter sample measurements with the Aerodyne aerosol mass spectrometer (offline-AMS) and the application of positive matrix factorization have significantly improved our capability to identify these sources and quantify their contributions. Such technique not only offers spatial and temporal broadening of organic aerosol (OA) measurements, but also allows for measurements of different aerodynamic sizes (PM1, PM2.5 and PM10). It is ideal to identify primary sources such as biomass burning, cooking or traffic and secondary such as oxygenated OA. Meanwhile, radiocarbon (14C) analysis provides an unequivocal distinction between fossil and non-fossil sources. The coupling of the two analyses provides a more robust source apportionment and a deeper investigation of the secondary OA origins.
Magadino, located in an alpine valley in Switzerland is characterized as a rural background site and suffers from high carbonaceous aerosol concentrations during winter which mainly stem from residential wood burning. Although previous studies have mostly focused on winter events, little is known about the seasonality of the pollutants and the influence of different sources thereon. Here we present offline AMS measurements coupled with 14C analysis for one yearly cycle in Magadino. The results show the quantified contributions of the dominant factors: biomass burning in winter and oxygenated OA during summer, as well as the seasonal patterns of fossil and non-fossil primary and secondary organic carbon. Traffic and cooking showed a rather constant annual behavior. The source apportionment on size segregated OA (PM10 and PM2.5) was crucial for the identification of a primary biological factor during summer.