Seasonal and diurnal changes in inorganic ions, carbonaceous matter and mass in ambient aerosol particles in an urban, background area

• Main Authors: Timonen, Hilkka, Aurela, Minna, Carbone, Samara, Saarnio, Karri, Frey, Anna, Saarikoski, Sanna, Teinilä, Kimmo, Kulmala, Markku, Hillamo, Risto
• Other Authors: Department of Physics
• Format: Article in Journal/Newspaper
• Language: English
• Published: Finnish Environment Institute 2016
• Subjects: FINE PARTICULATE MATTER; INTO-LIQUID SAMPLER; CHEMICAL-COMPOSITION; ELEMENTAL CARBON; AIR-POLLUTION; BLACK CARBON; LONG-RANGE; AIRBORNE MEASUREMENTS; SIZE DISTRIBUTIONS; ORGANIC-CARBON; 1172 Environmental sciences; Boreal Environment Research
• Online Access: http://hdl.handle.net/10138/160095

Concentration and composition of the fine particulate matter (PM) was measured using various online methods for 13 months in an urban, background area in Helsinki, Finland. Seasonal differences were found for ions and carbonaceous compounds. Biomass burning was found to increase inorganic ion and elemental carbon (EC) concentrations in winter, whereas organic carbon (OC) contribution was highest during summer due to secondary aerosol formation. Diurnal cycles, with maxima between 06:00 and 09:00, were recorded for EC and nitrate due to traffic emissions. In addition, the concentrations measured with the online and offline PM sampling devices were compared using regression analysis. In general, a good agreement (r(2) = 0.60-0.95) was found. During the year-long measurements, on average 65% of PM2.5 was identified by submicron chemical analyses (ions, OC, EC). As compared with filter measurements, the high resolution measurements provided important data on short pollution plumes and diurnal changes. Peer reviewed