Non-volatile residuals of newly formed atmospheric particles in the boreal forest
Open Access
- 12 February 2007
- journal article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 7 (3), 677-684
- https://doi.org/10.5194/acp-7-677-2007
Abstract
The volatility of sub-micrometer atmospheric aerosol particles was studied in a rural background environment in Finland using a combination of a heating tube and a scanning mobility particle sizer. The analysis focused on nanoparticles formed through nucleation which were subsequently observed during their growth in the diameter range between 5 and 60 nm. During the 6 days of new particle formation shown in detail, the concentrations of newly formed particles increased up to 10 000 cm−3. The number of nucleation mode particles measured after volatilization in the heating tube at 280°C was up to 90% of the total number under ambient conditions. Taking into account the absolute accuracy of the size distribution measurements, all ambient particles found in the rural atmosphere could have a non-volatile core after volatilization at 280°C. As the regional new particle formation events developed over time as a result of further vapor condensation, the newly formed particles grew at an average growth rate of 2.4±0.3 nm h−1. Importantly, the non-volatile cores of nucleation mode particles were also observed to grow over time, however, at a lower average growth rate of 0.6±0.3 nm h−1. One implication of the volatility analysis is that the newly formed particles, which have reached ambient diameters of 15 nm, are unlikely to consist of sulfuric acid, ammonium sulfate, and water alone. A relatively constant ratio between the growth rate of the ambient particles as well as their non-volatile cores indicates that non-volatile matter is formed only gradually in the growing particles. The non-volatile fraction of the particles showed some correlation with the ambient temperature. The composition and formation mechanism of this non-volatile material in nucleation mode particles are, to date, not known.Keywords
This publication has 22 references indexed in Scilit:
- Hygroscopic properties of ultrafine aerosol particles in the boreal forest: diurnal variation, solubility and the influence of sulfuric acidAtmospheric Chemistry and Physics, 2007
- Cluster activation theory as an explanation of the linear dependence between formation rate of 3nm particles and sulphuric acid concentrationAtmospheric Chemistry and Physics, 2006
- The contribution of sulfuric acid and non‐volatile compounds on the growth of freshly formed atmospheric aerosolsGeophysical Research Letters, 2005
- Identification of Polymers as Major Components of Atmospheric Organic AerosolsScience, 2004
- The Hohenpeissenberg aerosol formation experiment (HAFEX): a long-term study including size-resolved aerosol, H2SO4, OH, and monoterpenes measurementsAtmospheric Chemistry and Physics, 2003
- Physical characterization of aerosol particles during nucleation eventsTellus B: Chemical and Physical Meteorology, 2001
- Separation of volatile and non-volatile aerosol fractions by thermodesorption: instrumental development and applicationsJournal of Aerosol Science, 2001
- Measuring and simulating particulate organics in the atmosphere: problems and prospectsAtmospheric Environment, 2000
- Observations of ultrafine aerosol particle formation and growth in boreal forestGeophysical Research Letters, 1997
- A new electromobility spectrometer for the measurement of aerosol size distributions in the size range from 1 to 1000 nmJournal of Aerosol Science, 1991