Air Quality

August 2014
A container of instruments moves up the BAO tower while the NASA P3-B flies by during the multi-agency air quality study DISCOVER-AQ. Photo: W. von Dauster, NOAA

CSL researchers – international leaders in air quality research – are focused on understanding the details of the processes that can lead to air pollution. Polluted air prematurely kills more than 60,000 people in the United States every year, according to the U.S. Environmental Protection Agency.

In the 1980s, 10 years after the U.S. Clean Air Act put controls on emissions of many polluting chemicals, the air above some cities cleared up, yet other cities saw little change. CSL researchers and colleagues around the world began to realize that regional factors, from transportation patterns to emissions from natural vegetation, were critical in determining the effectiveness of clean-air strategies. With the help of powerful tools, including NOAA's WP-3D instrument-laden research aircraft, researchers and their colleagues began scrutinizing the air over U.S. cities and regions. The work has been and continues to be a key element in understanding basic chemical reactions that contribute to air pollution everywhere, as well as the unique chemistry and related processes in different regions.

Ozone – one of the primary pollutants in the "smog" that hangs over many cities – is one focus of CSL air quality research. High in the stratosphere, ozone is beneficial, but low in the troposphere, down near the Earth's surface, it is highly reactive and often destructive. Many atmospheric constituents, both natural and manmade, interact to affect tropospheric ozone levels, and understanding those sources of these constituents and the nature of their interactions provides a basis for determining how to address the problem of tropospheric ozone pollution.

CSL scientists also focus on understanding atmospheric aerosols (tiny airborne particles) and gaseous pollutants from a variety of perspectives: their effects on climate; their concentrations, sizes, and sources; and the "processing" of pollutants as they flow downstream from sources.