HR: 0800h
AN: A11A-0016    [Abstracts]
TI: Composition and Sourcing of Aerosol in the Mexico City Metropolitan Area with PIXE/PESA/STIM and Multivariate Analysis
AU: * Zuberi, B
EM: bzuberi@geo2tech.com
AF: Departments of Earth, Atmospheric and Planetary Sciences and of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AU: * Zuberi, B
EM: bzuberi@geo2tech.com
AF: GEO2 Technologies, 770 Boylston St., Boston, MA 02199 United States
AU: Johnson, K S
EM: kirstenj@mit.edu
AF: Departments of Earth, Atmospheric and Planetary Sciences and of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AU: de Foy, B
AF: Departments of Earth, Atmospheric and Planetary Sciences and of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AU: Molina, L T
AF: Departments of Earth, Atmospheric and Planetary Sciences and of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AU: Molina, M J
AF: Departments of Earth, Atmospheric and Planetary Sciences and of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AU: Shutthanandan, V
AF: William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, POB 999, K8-88, Richland, WA 99352 United States
AU: Xie, Y
AF: William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, POB 999, K8-88, Richland, WA 99352 United States
AU: Disselkamp, R
AF: William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, POB 999, K8-88, Richland, WA 99352 United States
AU: Jimenez, J
AF: University of Colorado-Boulder, Department of Chemistry & Biochemistry; and CIRES, UCB 216, Boulder, CO 80309 United States
AU: Dzepina, K
AF: University of Colorado-Boulder, Department of Chemistry & Biochemistry; and CIRES, UCB 216, Boulder, CO 80309 United States
AU: Salcedo, D
AF: Universidad Aut"rnoma del Estado de Morelos, Av. Universidad #1001, Cuernavaca, 62210 Mexico
AB: Particulate matter $<$2.5 $\mu$m in diameter (PM2.5) is a serious concern in megacity air pollution for its possible effects on human health and climate, and potential role in heterogeneous chemical processes. Determining the chemical composition of PM2.5 is essential in assessing their effects, and the various aerosol emission sources must be identified in order to develop effective pollution control strategies. Samples of PM2.5 were collected in a southeastern site in the Mexico City Metropolitan Area (MCMA) during the MCMA-2003 campaign between April 3 - May 4, 2003 with a 3-stage IMPROVED Cascade DRUM Impactor in size ranges 0.07 - 0.34 $\mu$m (Stage C), 0.34 - 1.15 $\mu$m (Stage B), and 1.15 - 2.5 $\mu$m (Stage A). Analyses by Proton-Induced X-ray Emission (PIXE), Proton-Elastic Scattering Analysis (PESA) and Scanning Transmission Ion Microscopy (STIM) were performed to provide 6-hr averaged concentrations of elements $>$ Na, H, and total aerosol mass, respectively, for each size range. Multivariate analysis including Positive Matrix Factorization (PMF) was applied to group elements by common factors to identify possible aerosol emission sources within each size range. Sudden increases in elements characteristic of industrial emissions and fuel oil suggest manufacturing sources to the north of the city whereas soil aerosols originate from more rural areas to the south. Sulfur contributes to a significant fraction of PM2.5, in agreement with complementary aerosol measurements taken during the campaign. Additional trends and diurnal profiles observed for Mexico City aerosol are presented.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0322 Constituent sources and sinks
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting