Internally mixed soot, sulfates, and organic matter in aerosol particles from Mexico City

By K. Adachi, Peter R. Buseck. 2008

295 citations recorded by the source corpus.

Soot particles, which are aggregated carbonaceous spherules with graphitic structures, are major aerosol constituents that result from burning of fossil fuel, biofuel, and biomass. Their properties commonly change through reaction with other particles or gases, resulting in complex internal mixtures. Using a transmission electron microscope (TEM) for both imaging and chemical analysis, we measured ~8000 particles (25 samples) with aerodynamic diameters from 0.05 to 0.3 μm that were collected in March 2006 from aircraft over Mexico City (MC) and adjacent areas. Most particles are coated, consist of aggregates, or both. For example, almost all analyzed particles contain S and 70% also contain K, suggesting coagulation and condensation of sulfates and particles derived from biomass and biofuel burning. In the MC plumes, over half of all particles contained soot coated by organic matter and sulfates. The median value of the soot volume fraction in such coated particles is about 15%. In contrast to the assumptions used in many climate models, the soot particles did not become compact even when coated. Moreover, about 80% by volume of the particles consisting of organic matter with sulfate also contained soot, indicating the important role of soot in the formation of secondary aerosol particles. Coatings on soot particles can amplify their light absorption, and coagulation with sulfates changes their hygroscopic properties, resulting in shorter lifetimes. Through changes in their optical and hygroscopic properties, internally mixed soot particles have a greater effect on the regional climate of MC than uncoated soot particles.

Subfields: Atmospheric Science, Automotive Engineering, Health, Toxicology and Mutagenesis

View Paper: https://www.semanticscholar.org/paper/63cb6d30b9ce530a00375c960a2e6d11c98c1cee

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atmospheric Science

1. Xiaohong Liu
2. Steven Ghan
3. R. Easter
4. Peter R. Buseck
5. K. Adachi
6. Weijun Li
7. S. Chung
8. Longyi Shao

In Automotive Engineering

1. Weijun Li
2. Longyi Shao
3. S. Chung
4. Peter R. Buseck
5. K. Adachi

In Health, Toxicology and Mutagenesis

1. Peter R. Buseck
2. K. Adachi
3. Weijun Li
4. S. Chung
5. Longyi Shao
6. R. Easter
7. R. Zaveri

Citations in the corpus

• Observations of the spectral dependence of linear particle depolarization ratio of aerosols using NASA Langley airborne High Spectral Resolution Lidar (2015, background): “2, and a monomer radius of 25 nm, values chosen to be consistent with the findings for soot aerosol in Mexico City (Adachi and Buseck, 2008).”
• Morphology and mixing state of aged soot particles at a remote marine free troposphere site: Implications for optical properties (2015, methodology): “They were categorized into four groups: (1) embedded [Adachi and Buseck, 2008], when soot was fully engulfed in coating material; (2) partly coated, when the coating material filled the soot internal voids; (3) thinly coated, when coating on soot was minimal; and (4) partially encapsulated, when…”
• Toward a Minimal Representation of Aerosols in Climate Models: Comparative Decomposition of Aerosol Direct, Semidirect, and Indirect Radiative Forcing (2012, background): “2005) while aged particles are often composed of internal mixtures of black carbon coated with sulfates and other secondary material (Adachi and Buseck 2008).”
• Transmission electron microscopy study of aerosol particles from the brown hazes in northern China (2009, methodology): “[28] Soot and organic materials from biomass burning were internally mixed with K- and S-rich particles [Niemi et al., 2005; Adachi and Buseck, 2008 ].”
• Shapes of soot aerosol particles and implications for their effects on climate (2010, methodology): “Because of the rapid ventilation of the MC basin, the MC plume samples probably aged for less than 1 day and those from outside the plume are older [ Adachi and Buseck, 2008 ].”
• A review of biomass burning: Emissions and impacts on air quality, health and climate in China. (2017, background): “Several TEM studies have shown thebiomass particleswith organic coatingwerewidespread in urban atmosphere (Adachi and Buseck, 2008; Li et al., 2010b).”