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Title: Chemical Imaging of Ambient Aerosol Particles: Observational Constraints on Mixing State Parameterization

Abstract

A new parameterization for quantifying the mixing state of aerosol populations has been applied for the first time to samples of ambient particles analyzed using spectro-microscopy techniques. Scanning transmission x-ray microscopy/near edge x-ray absorption fine structure (STXM/NEXAFS) and computer controlled scanning electron microscopy/energy dispersive x-ray spectroscopy (CCSEM/EDX) were used to probe the composition of the organic and inorganic fraction of individual particles collected on June 27th and 28th during the 2010 Carbonaceous Aerosols and Radiative Effects (CARES) study in the Central Valley, California. The first field site, T0, was located in downtown Sacramento, while T1 was located near the Sierra Nevada Mountains. Mass estimates of the aerosol particle components were used to calculate mixing state metrics, such as the particle-specific diversity, bulk population diversity, and mixing state index, for each sample. Both microscopy imaging techniques showed more changes over these two days in the mixing state at the T0 site than at the T1 site. The STXM data showed evidence of changes in the mixing state associated with a build-up of organic matter confirmed by collocated measurements and the largest impact on the mixing state was due to an increase in soot dominant particles during this build-up. The CCSEM/EDX analysismore » showed the presence of two types of particle populations; the first was dominated by aged sea salt particles and had a higher mixing state index (indicating a more homogeneous population), the second was dominated by carbonaceous particles and had a lower mixing state index.« less

Authors:
; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1229980
Report Number(s):
PNNL-SA-109208
Journal ID: ISSN 2169-8996; 47949; 48009; 47937; KP1701000
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research. Atmospheres
Additional Journal Information:
Journal Volume: 120; Journal Issue: 18; Journal ID: ISSN 2169-8996
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English
Subject:
Environmental Molecular Sciences Laboratory

Citation Formats

O'Brien, Rachel, Wang, Bingbing, Laskin, Alexander, Riemer, Nicole, West, Matthew, Zhang, Qi, Sun, Yele, Yu, Xiao-Ying, Alpert, Peter A., Knopf, Daniel A., Gilles, Mary K., and Moffet, Ryan. Chemical Imaging of Ambient Aerosol Particles: Observational Constraints on Mixing State Parameterization. United States: N. p., 2015. Web. doi:10.1002/2015JD023480.
O'Brien, Rachel, Wang, Bingbing, Laskin, Alexander, Riemer, Nicole, West, Matthew, Zhang, Qi, Sun, Yele, Yu, Xiao-Ying, Alpert, Peter A., Knopf, Daniel A., Gilles, Mary K., & Moffet, Ryan. Chemical Imaging of Ambient Aerosol Particles: Observational Constraints on Mixing State Parameterization. United States. doi:10.1002/2015JD023480.
O'Brien, Rachel, Wang, Bingbing, Laskin, Alexander, Riemer, Nicole, West, Matthew, Zhang, Qi, Sun, Yele, Yu, Xiao-Ying, Alpert, Peter A., Knopf, Daniel A., Gilles, Mary K., and Moffet, Ryan. Mon . "Chemical Imaging of Ambient Aerosol Particles: Observational Constraints on Mixing State Parameterization". United States. doi:10.1002/2015JD023480.
@article{osti_1229980,
title = {Chemical Imaging of Ambient Aerosol Particles: Observational Constraints on Mixing State Parameterization},
author = {O'Brien, Rachel and Wang, Bingbing and Laskin, Alexander and Riemer, Nicole and West, Matthew and Zhang, Qi and Sun, Yele and Yu, Xiao-Ying and Alpert, Peter A. and Knopf, Daniel A. and Gilles, Mary K. and Moffet, Ryan},
abstractNote = {A new parameterization for quantifying the mixing state of aerosol populations has been applied for the first time to samples of ambient particles analyzed using spectro-microscopy techniques. Scanning transmission x-ray microscopy/near edge x-ray absorption fine structure (STXM/NEXAFS) and computer controlled scanning electron microscopy/energy dispersive x-ray spectroscopy (CCSEM/EDX) were used to probe the composition of the organic and inorganic fraction of individual particles collected on June 27th and 28th during the 2010 Carbonaceous Aerosols and Radiative Effects (CARES) study in the Central Valley, California. The first field site, T0, was located in downtown Sacramento, while T1 was located near the Sierra Nevada Mountains. Mass estimates of the aerosol particle components were used to calculate mixing state metrics, such as the particle-specific diversity, bulk population diversity, and mixing state index, for each sample. Both microscopy imaging techniques showed more changes over these two days in the mixing state at the T0 site than at the T1 site. The STXM data showed evidence of changes in the mixing state associated with a build-up of organic matter confirmed by collocated measurements and the largest impact on the mixing state was due to an increase in soot dominant particles during this build-up. The CCSEM/EDX analysis showed the presence of two types of particle populations; the first was dominated by aged sea salt particles and had a higher mixing state index (indicating a more homogeneous population), the second was dominated by carbonaceous particles and had a lower mixing state index.},
doi = {10.1002/2015JD023480},
journal = {Journal of Geophysical Research. Atmospheres},
issn = {2169-8996},
number = 18,
volume = 120,
place = {United States},
year = {2015},
month = {9}
}