When it comes to global air pollution, what goes around comes around. Air pollution from factories, traffic, and power plants in Asia wafts over the Pacific Ocean to the United States, while pollutants produced in the United States wind up in Europe.

In 2006, a team of NCAR researchers convened in Mexico City for MIRAGE, a study of the chemical and physical transformation of air pollution in urban areas and its impact on air quality, ecosystems, and climate. Another MIRAGE field campaign kicks off this month, this time in Shanghai, China's largest city.

A new study led by NCAR scientist David Edwards is the first to apply the concept of Observing System Simulation Experiments to chemical weather (predicting pollution events and variability in the atmosphere’s chemical composition).

Geoffrey Tyndall, NCAR's Atmospheric Chemistry Division • As a physical chemist, Tyndall likes "quantifying things, putting numbers on them—how fast does this go, and why is this reaction faster than that one?"

NCAR scientist Fei Chen is collaborating with colleagues at China’s Institute of Urban Meteorology to explore how growth in Beijing is changing the city’s summer rainfall patterns, focusing specifically on the relationship between urban expansion, aerosols, and summer rainfall.