Prevalence of ketonic carbonyl groups in submicron particles from a boreal forest in Hyytiälä, Finland during HUMPPA-COPEC 2010

The boreal forest in Hyytiälä, Finland, is a unique environment with respect to biogenic secondary organic aerosols. This site has hosted numerous field studies during the last 10 years, and nucleation events have frequently been observed above the canopy. Measurements of particle-phase organic functional groups and inorganic ions collected during the HUMPPA-COPEC10 campaign from July 12 - August 12, 2010, are compared with gas-phase biogenic and inorganic aerosol precursors to elucidate contributing factors on secondary organic aerosol formation in the Scots pine forest of Hyytiälä, Finland. Observed organic functional groups from Fourier transform infrared (FTIR) analysis of PM1 particles include alkane, carboxylic acid, organic hydroxyl, organonitrate, non-carboxylic acid carbonyl, and primary amine groups. Organic particles were also detected by aerosol mass spectrometry (AMS) and the two methods were shown to compare well. Organic particle composition is studied through a combination of factor analysis of organic functional groups (FTIR) and organic mass fragments (AMS).