Hygroscopicity, CCN and volatility properties of submicron atmospheric aerosol in a boreal forest environment during the summer of 2010

TY - JOUR

T1 - Hygroscopicity, CCN and volatility properties of submicron atmospheric aerosol in a boreal forest environment during the summer of 2010

AU - Hong, J.

AU - Häkkinen, S. A. K.

AU - Paramonov, M.

AU - Äijälä, M.

AU - Hakala, J.

AU - Nieminen, T.

AU - Mikkilä, J.

AU - Prisle, N. L.

AU - Kulmala, M.

AU - Riipinen, I.

AU - Bilde, M.

AU - Kerminen, V. -M.

AU - Petäjä, T.

PY - 2014

Y1 - 2014

N2 - A Volatility-Hygroscopicity Tandem Differential Mobility Analyzer (VH-TDMA) was applied to study the hygroscopicity and volatility properties of submicron atmospheric aerosol particles in a boreal forest environment in Hyytiala, Finland during the summer of 2010. Aitken and accumulation mode internally mixed particles (50 nm, 75 nm and 110 nm in diameter) were investigated. Hygroscopicity was found to increase with particle size. The relative mass fraction of organics and SO42- is probably the major contributor to the fluctuation of the hygroscopicity for all particle sizes. The Cloud Condensation Nuclei Counter (CCNC)-derived hygroscopicity parameter kappa was observed to be slightly higher than kappa calculated from VH-TDMA data under sub-saturated conditions, potential reasons for this behavior are discussed shortly. Also, the size-resolved volatility properties of particles were investigated. Upon heating, more small particles evaporated compared to large particles. There was a significant amount of aerosol volume (non-volatile material) left, even at heating temperatures of 280 degrees C. Using size resolved volatility-hygroscopicity analysis, we concluded that there was always hygroscopic material remaining in the particles at different heating temperatures, even at 280 degrees C. This indicates that the observed non-volatile aerosol material did not consist solely of black carbon.

AB - A Volatility-Hygroscopicity Tandem Differential Mobility Analyzer (VH-TDMA) was applied to study the hygroscopicity and volatility properties of submicron atmospheric aerosol particles in a boreal forest environment in Hyytiala, Finland during the summer of 2010. Aitken and accumulation mode internally mixed particles (50 nm, 75 nm and 110 nm in diameter) were investigated. Hygroscopicity was found to increase with particle size. The relative mass fraction of organics and SO42- is probably the major contributor to the fluctuation of the hygroscopicity for all particle sizes. The Cloud Condensation Nuclei Counter (CCNC)-derived hygroscopicity parameter kappa was observed to be slightly higher than kappa calculated from VH-TDMA data under sub-saturated conditions, potential reasons for this behavior are discussed shortly. Also, the size-resolved volatility properties of particles were investigated. Upon heating, more small particles evaporated compared to large particles. There was a significant amount of aerosol volume (non-volatile material) left, even at heating temperatures of 280 degrees C. Using size resolved volatility-hygroscopicity analysis, we concluded that there was always hygroscopic material remaining in the particles at different heating temperatures, even at 280 degrees C. This indicates that the observed non-volatile aerosol material did not consist solely of black carbon.

KW - CLOUD CONDENSATION NUCLEI

KW - SECONDARY ORGANIC AEROSOL

KW - SIZE-RESOLVED MEASUREMENTS

KW - DROPLET ACTIVATION

KW - MASS-SPECTROMETER

KW - SULFURIC-ACID

KW - AMMONIUM-SULFATE

KW - PARTICLES

KW - GROWTH

KW - TDMA

U2 - 10.5194/acp-14-4733-2014

DO - 10.5194/acp-14-4733-2014

M3 - Journal article

SN - 1680-7316

VL - 14

SP - 4733

EP - 4748

JO - Atmospheric Chemistry and Physics

JF - Atmospheric Chemistry and Physics

IS - 9

ER -