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Sulfate Lens Enhances Climate Warming Properities of Atmospheric Soot

Ship Smoke Harms Coastal Air Quality

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The source of smoke particles is more clear. Satellite images taken during the experiment show a swath of fires burning in the hills surrounding Mexico City. By matching the types of smog bits they captured to the wind patterns each day, the team was able to attribute the afternoon influx of freshly burned biomass to these distant fires. Winds picked up each morning after 11:00 am, blowing the industrial waste away and bringing smoke from the fires to the south, they report in the journal Atmospheric Chemistry and Physics on August 5, 2008.

Cooking fires contribute to atmospheric soot.

Credit: Kimberly Prather

Fuel burned by street vendors also contributes to smoke in the city, the scientists say. "A lot of people use charcoal on the streets to cook their food," Moffet said, "not only in Mexico City but also in cities in China and India that also struggle with air quality."

The project was part of the MILAGRO campaign (the Megacity Initiative: Local and Global Research Observations) organized by the Molina Center for Energy and the environment and conducted in March 2006 when scientists from more than 60 research institutions descended on Mexico City to study the composition of its smog and how it is transformed and transported regionally and globally.

The National Science Foundation, Department of Energy, and the Mexico City Metropolitan Area Environmental Commission supported the study of metal aerosols. The National Science Foundation also supported the study of smoke particles.

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