A major field project in the Eastern United States, supported by NCAR, seeks to better understand air pollution during winter.

Scientists find unequivocal evidence that thunderstorms move ozone from the stratosphere down toward Earth's surface, affecting air quality and climate.

A circulation change has boosted concentrations of hydrogen chloride (HCl), the main reservoir of chlorine in the stratosphere, by several percent over much of the Northern Hemisphere since 2007.

In a surprising finding, a research team concludes that the dominant "detergent" in the atmosphere is equally abundant in the northern and southern hemispheres.

Ozone pollution in India is damaging millions of tons of the country’s major crops, according to a new study by an international team of researchers. The pollution caused losses of more than $1 billion in a single year, destroying enough food to feed an estimated 94 million people.