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Insights into the growth of newly formed particles in a subtropical urban environment

Citation

Salimi, F and Crilley, LR and Stevanovic, S and Ristovski, Z and Mazaheri, M and He, C and Johnson, G and Ayoko, G and Morawska, L, Insights into the growth of newly formed particles in a subtropical urban environment, Atmoshpheric chemistry and physics, 15 pp. 13475-13485. ISSN 1680-7316 (2014) [Refereed Article]


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Copyright Statement

Author(s) 2015. Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0) http://creativecommons.org/licenses/by/3.0/

DOI: doi:10.5194/acp-15-13475-2015

Abstract

The role of different chemical compounds, particularly organics, involved in the new particle formation (NPF) and its consequent growth are not fully understood. Therefore, this study was conducted to investigate the chemical composition of aerosol particles during NPF events in an urban subtropical environment. Aerosol chemical composition was measured along with particle number size distribution (PNSD) and several other air quality parameters at five sites across an urban subtropical environment. An Aerodyne compact Time-of-Flight Aerosol Mass Spectrometer (c-ToF-AMS) and a TSI Scanning Mobility Particle Sizer (SMPS) measured aerosol chemical composition (particles above 50 nm in vacuum aerodynamic diameter) and PNSD (particles within 9414 nm in mobility diameter), respectively. Five NPF events, with growth rates in the range 3.3 4.6 nm, were detected at two of the sites. The NPF events happened on relatively warmer days with lower condensation sink (CS). Temporal percent fractions of organics increased after the particles grew enough to have a signifi- cant contribution to particle volume, while the mass fraction of ammonium and sulfate decreased. This uncovered the important role of organics in the growth of newly formed particles. Three organic markers, factors f43, f44 and f57, were calculated and the f44 vs. f43 trends were compared between nucleation and non-nucleation days. K-means cluster analysis was performed on f44 vs. f43 data and it was found that they follow different patterns on nucleation days compared to non-nucleation days, whereby f43 decreased for vehicle-emission-generated particles, while both f44 and f43 decreased for NPF-generated particles. It was found for the first time that vehicle-generated and newly formed particles cluster in different locations on f44 vs. f43 plot, and this finding can be potentially used as a tool for source apportionment of measured particles.

Item Details

Item Type:Refereed Article
Keywords:newly formed particles, urban environment, chemistry
Research Division:Earth Sciences
Research Group:Atmospheric Sciences
Research Field:Atmospheric Aerosols
Objective Division:Environment
Objective Group:Air Quality
Objective Field:Urban and Industrial Air Quality
Author:Salimi, F (Dr Farhad Salimi)
ID Code:105248
Year Published:2014
Web of Science® Times Cited:1
Deposited By:Menzies Institute for Medical Research
Deposited On:2015-12-16
Last Modified:2016-05-19
Downloads:33 View Download Statistics

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