Title Hygroscopicity and chemical composition of Antarctic sub-micrometre aerosol particles and observations of new particle formation
Author Asmi, E.; Frey, A.; Virkkula, A.; Ehn, M.; Manninen, H.E.; Timonen, H.; Tolonen- Kivimaki, O.; Aurela, M.; Hillamo, R.; Kulmala, M.
Author Affil Asmi, E., Finnish Meteorological Institute, Research and Development, Helsinki, Finland. Other: University of Helsinki, Finland
Source Atmospheric Chemistry and Physics, 10(9), p.4253-4271, . Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2010
Notes In English. Published in Atmospheric Chemistry and Physics Discussions: 17 December 2009, http://www.atmos-chem-phys- discuss.net/9/27303/2009/acpd-9-27303-2009.ht ml; accessed in May, 2011. 98 refs. Ant. Acc. No: 91468. GeoRef Acc. No: 310052
Index Terms aerosols; boundary layer; chemical composition; condensation; distribution; geochemistry; humidity; hydrocarbons; hygroscopicity; ions; meteorology; particles; snow; water vapor; wind (meteorology); Antarctica; Southern Ocean; Aboa Station; acids; aliphatic hydrocarbons; alkanes; ammonium sulfate; carbon; inorganic acids; methane; methanesulfonic acid; organic carbon; organic compounds; oxalates; oxidation; relative humidity; sea water; seasonal variations; size; sulfuric acid; troposphere; volatiles; winds
Abstract The Antarctic near-coastal sub- micrometre aerosol particle features in summer were characterised based on measured data on aerosol hygroscopicity, size distributions, volatility and chemical ion and organic carbon mass concentrations. Hysplit model was used to calculate the history of the air masses to predict the particle origin. Additional measurements of meteorological parameters were utilised. The hygroscopic properties of particles mostly resembled those of marine aerosols. The measurements took place at 130 km from the Southern Ocean, which was the most significant factor affecting the particle properties. This is explained by the lack of additional sources on the continent of Antarctica. The Southern Ocean was thus a likely source of the particles and nucleating and condensing vapours. The particles were very hygroscopic (HGF 1.75 at 90 nm) and very volatile. Most of the sub-100 nm particle volume volatilised below 100C. Based on chemical data, particle hygroscopic and volatile properties were explained by a large fraction of non-neutralised sulphuric acid together with organic material. The hygroscopic growth factors assessed from chemical data were similar to measured. Hygroscopicity was higher in dry continental air masses compared with the moist marine air masses. This was explained by the aging of the marine organic species and lower methanesulphonic acid volume fraction together with the changes in the inorganic aerosol chemistry as the aerosol had travelled long time over the continental Antarctica. Special focus was directed in detailed examination of the observed new particle formation events. Indications of the preference of negative over positive ions in nucleation could be detected. However, in a detailed case study, the neutral particles dominated the particle formation process. Freshly nucleated particles had the smallest hygroscopic growth factors, which increased subsequent to particle aging.
URL http://www.atmos-chem-phys.net/10/4253/2010/acp-10-4253-2010.pdf
Publication Type journal article
Record ID 65006800