Properties of secondary organic aerosol in the ambient atmosphere: sources, formation, and partitioning

This thesis characterizes properties of ambient secondary organic aerosol (SOA), an important and abundant component of particulate matter. The findings presented in this thesis are significant because they represent the results from ambient measurements, which are relatively scarce, and because th...

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Main Author: Hennigan, Christopher James
Published: Georgia Institute of Technology 2009
Subjects:
SOA
Air
Online Access:http://hdl.handle.net/1853/26598
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spelling ndltd-GATECH-oai-smartech.gatech.edu-1853-265982013-01-07T20:29:46ZProperties of secondary organic aerosol in the ambient atmosphere: sources, formation, and partitioningHennigan, Christopher JamesAtmospheric chemistryAerosolSOAPartitioningSecondary organic aerosolVolatilityAtmospheric aerosolsAirPollutionParticles Environmental aspects.This thesis characterizes properties of ambient secondary organic aerosol (SOA), an important and abundant component of particulate matter. The findings presented in this thesis are significant because they represent the results from ambient measurements, which are relatively scarce, and because they report on properties of SOA that, until now, were highly uncertain. The analyses utilized the fraction of particulate organic carbon that was soluble in water (WSOCp) to approximate SOA concentrations in two largely different urban environments, Mexico City and Atlanta. In Mexico City, measurements of atmospheric gases and fine particle chemistry were made at a site ~ 30 km down wind of the city center. Using box model analyses and a comparison to ammonium nitrate aerosol, a species whose thermodynamic properties are generally understood, the morning formation and mid-day evaporation of SOA are investigated. In Atlanta, simultaneous measurements of WSOCp and water-soluble organic carbon in the gas phase (WSOCg) were carried out for an entire summer to investigate the sources and partitioning of WSOC. The results suggest that both WSOCp and WSOCg were secondary and biogenic, except possibly in several strong biomass burning events. The gas/particle partitioning of WSOC in Atlanta was investigated through the parameter, Fp, which represented the fraction of WSOC in the particle phase. Factors that appear to influence WSOC partitioning in Atlanta include ambient relative humidity and the WSOCp mass concentration. There was also a relationship between the NOx concentration and Fp, though this was not likely related to the partitioning process. Temperature did not appear to impact Fp, though this may have been due to positive relationships WSOCp and WSOCg each exhibited with temperature. Neither the total Organic Carbon aerosol mass concentration nor the ozone concentration impacted WSOC partitioning.Georgia Institute of Technology2009-01-22T15:49:06Z2009-01-22T15:49:06Z2008-10-14Dissertationhttp://hdl.handle.net/1853/26598
collection NDLTD
sources NDLTD
topic Atmospheric chemistry
Aerosol
SOA
Partitioning
Secondary organic aerosol
Volatility
Atmospheric aerosols
Air
Pollution
Particles Environmental aspects.
spellingShingle Atmospheric chemistry
Aerosol
SOA
Partitioning
Secondary organic aerosol
Volatility
Atmospheric aerosols
Air
Pollution
Particles Environmental aspects.
Hennigan, Christopher James
Properties of secondary organic aerosol in the ambient atmosphere: sources, formation, and partitioning
description This thesis characterizes properties of ambient secondary organic aerosol (SOA), an important and abundant component of particulate matter. The findings presented in this thesis are significant because they represent the results from ambient measurements, which are relatively scarce, and because they report on properties of SOA that, until now, were highly uncertain. The analyses utilized the fraction of particulate organic carbon that was soluble in water (WSOCp) to approximate SOA concentrations in two largely different urban environments, Mexico City and Atlanta. In Mexico City, measurements of atmospheric gases and fine particle chemistry were made at a site ~ 30 km down wind of the city center. Using box model analyses and a comparison to ammonium nitrate aerosol, a species whose thermodynamic properties are generally understood, the morning formation and mid-day evaporation of SOA are investigated. In Atlanta, simultaneous measurements of WSOCp and water-soluble organic carbon in the gas phase (WSOCg) were carried out for an entire summer to investigate the sources and partitioning of WSOC. The results suggest that both WSOCp and WSOCg were secondary and biogenic, except possibly in several strong biomass burning events. The gas/particle partitioning of WSOC in Atlanta was investigated through the parameter, Fp, which represented the fraction of WSOC in the particle phase. Factors that appear to influence WSOC partitioning in Atlanta include ambient relative humidity and the WSOCp mass concentration. There was also a relationship between the NOx concentration and Fp, though this was not likely related to the partitioning process. Temperature did not appear to impact Fp, though this may have been due to positive relationships WSOCp and WSOCg each exhibited with temperature. Neither the total Organic Carbon aerosol mass concentration nor the ozone concentration impacted WSOC partitioning.
author Hennigan, Christopher James
author_facet Hennigan, Christopher James
author_sort Hennigan, Christopher James
title Properties of secondary organic aerosol in the ambient atmosphere: sources, formation, and partitioning
title_short Properties of secondary organic aerosol in the ambient atmosphere: sources, formation, and partitioning
title_full Properties of secondary organic aerosol in the ambient atmosphere: sources, formation, and partitioning
title_fullStr Properties of secondary organic aerosol in the ambient atmosphere: sources, formation, and partitioning
title_full_unstemmed Properties of secondary organic aerosol in the ambient atmosphere: sources, formation, and partitioning
title_sort properties of secondary organic aerosol in the ambient atmosphere: sources, formation, and partitioning
publisher Georgia Institute of Technology
publishDate 2009
url http://hdl.handle.net/1853/26598
work_keys_str_mv AT henniganchristopherjames propertiesofsecondaryorganicaerosolintheambientatmospheresourcesformationandpartitioning
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