Processing of soot in an urban environment: Case study from the Mexico City Metropolitan Area

147Citations
Citations of this article
81Readers
Mendeley users who have this article in their library.
Get full text

Abstract

Chemical composition, size, and mixing state of atmospheric particles are critical in determining their effects on the environment. There is growing evidence that soot aerosols play a particularly important role in both climate and human health, but still relatively little is known of their physical and chemical nature. In addition, the atmospheric residence times and removal mechanisms for soot are neither well understood nor adequately represented in regional and global climate models. To investigate the effect of locality and residence time on properties of soot and mixing state in a polluted urban environment, particles of diameter 0.2-2.0 μm were collected in the Mexico City Metropolitan Area (MCMA) during the MCMA-2003 Field Campaign from various sites within the city. Individual particle analysis by different electron microscopy methods coupled with energy dispersed x-ray spectroscopy, and secondary ionization mass spectrometry show that freshly-emitted soot particles become rapidly processed in the MCMA. Whereas fresh particulate emissions from mixed-traffic are almost entirely carbonaceous, consisting of soot aggregates with liquid coatings suggestive of unburned lubricating oil and water, ambient soot particles which have been processed for less than a few hours are heavily internally mixed, primarily with ammonium sulfate. Single particle analysis suggests that this mixing occurs through several mechanisms that require further investigation. In light of previously published results, the internally-mixed nature of processed soot particles is expected to affect heterogeneous chemistry on the soot surface, including interaction with water during wet-removal. © 2005 Author(s). This work is licensed under a Creative Commons License.

Cite

CITATION STYLE

APA

Johnson, K. S., Zuberi, B., Molina, L. T., Molina, M. J., Iedema, M. J., Cowin, J. P., … Laskin, A. (2005). Processing of soot in an urban environment: Case study from the Mexico City Metropolitan Area. Atmospheric Chemistry and Physics, 5(11), 3033–3043. https://doi.org/10.5194/acp-5-3033-2005

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free