Characterization of Fine Particles by the ASCM at a Residential Area in Finland
MINNA AURELA, Sanna Saarikoski, Anna Frey, Jarkko V. Niemi, Hilkka Timonen, Samara Carbone and Risto Hillamo
Finnish Meteorological Institute
Abstract Number: 349
Working Group: Aerosol Chemistry
Last modified: April 4, 2011
Residential wood combustion has been identified as a major contributor to air pollution in number of cities during cold seasons. At an urban background area in Helsinki 41% of OC has been estimated to originate from biomass combustion during winter. In this study fine particle aerosol chemical composition was measured using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) between February 17 and March 16, 2011 at a residential area approximately 20 km north-east from downtown of Helsinki. The site is surrounded by detached houses with their own fireplaces. There are no main through roads at the area but the nearest motorway is approximately 1500 m east of the site. Black carbon was measured with an aethalometer between March 1 and March 16 and PM$_(2.5) mass and NO$_x were monitored through the whole campaign.
The temperature was very low over the first week of the campaign and organics measured with the ACSM, and PM$_(2.5) mass concentrations had very clear cycle with higher concentrations during the evenings and nights than during day time. Also the mass to charge (m/z) ratio of 60, which is typically used as biomass burning tracer, increased. When the temperature increased organics and m/z 60 decreased very clearly. During the warmer conditions no major local sources were detected. At the end of campaign long range transport emissions had great effect on the concentrations.