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June 21, 1999 — Air pollution and its effects take a toll on the whole country, but especially in areas that are hot and humid. It can damage crops and forests and affect human health and scenic visibility. This summer, scientists from government and academia will pool their resources in an air quality study that will provide a better understanding of the basic chemical, meteorological, and transport processes that cause air pollution. NOAA's contribution is part of its Health of the Atmosphere air quality research program.

The Southern Oxidants Study (SOS) is a cooperative effort among universities and federal, state, and local government environmental and regulatory agencies to investigate air pollution from mid-June to mid-July. Operating out of Nashville, Tenn., scientists will investigate the processes responsible for the formation of ozone pollution and fine particulate matter (PM) that may be a factor in many health-related problems, as well as crop and forest damage. This research will provide critical background information to policy makers who are developing solutions to deal more effectively with these problems. "Although the nation has made considerable progress in managing air pollution during the past thirty years," says North Carolina State University's Dr. Ellis Cowling, "some of our most challenging problems still remain."

Using planes, helicopters and air monitoring stations located throughout the South, scientists will collect air samples to assess the physical and chemical characteristics of fine particulate matter and ozone. "The combined activities of this study provide an unparalleled opportunity to describe the production and distribution of ozone and PM throughout the Southeast with a level of detail that has hitherto not been possible," says James Meagher, of NOAA's Aeronomy Laboratory in Boulder, Colo. Chief scientist for the project, Meagher says that the improved insights and new scientific findings that are expected will translate directly into better management strategies for these two pollutants.

In the late 1980's, scientists realized that the South had unique air quality management problems caused by warm temperatures, high humidity, stagnant air and natural emissions of hydrocarbons from the South's large rural and urban forests. "Large urban heat islands, such as Nashville or Atlanta, surrounded by lush vegetation and forests, cause a unique air pollution mix of human-caused and natural emissions," said Meagher.

NOAA's participation involves several Laboratories of NOAA's Office of Oceanic and Atmospheric Research (OAR): the Aeronomy Laboratory, Environmental Technology Laboratory, Air Resources Laboratory, and Climate Monitoring and Diagnostics Laboratory. NOAA has a long history of participation in SOS, which is a coordinated, long-term research program focusing on gaining a better insight to the formation, accumulation and, therefore, effective management of pollution in the South.

During 1997, the Environmental Protection Agency introduced three regulatory plans to address the most serious air quality problems in the nation. These include a new National Ambient Air Quality Standard for ozone, new standards for particulate matter, and proposals for new regional haze regulations to protect and improve visibility in the national parks and wilderness areas of the country. These actions are expected to result in a significant increase in the number of areas regarded as "nonattainment" for ozone. However, the new regulations are presently under intense scrutiny and judicial review. This heightens the need for ozone and PM management strategies to be based on sound science, which is the goal for both NOAA's Health of the Atmosphere research and SOS.

During the study, aircraft including NOAA's WP-3D Orion hurricane hunter (serving as flagship), the Tennessee Valley Authority's Bell helicopter, the Pacific Northwest National Laboratory's Gulfstream-1 (G-1), and a DeHavilland Caribou will be taking a series of coordinated chemical and meteorological measurements. As air pollution is a problem that doesn't go away when the sun sets, investigators from the Pacific Northwest National Laboratory will use the G-1 aircraft to make measurements of ozone and aerosols at night, and intercomparisons will be made with the daytime flights of the other aircraft. The planes will be used to collect air samples over a wide area of the Southeast and Midwestern United States to assess to what degree ozone or fine particulate pollution is a regional or a local problem. The researchers will also use ground-based meteorological and air quality monitoring stations throughout Nashville and Middle Tennessee.

During the study, the NOAA P-3—which has been reconfigured by NOAA's Aircraft Operations Center in Tampa, Fla., from a hurricane research platform to a flying air chemistry laboratory—will make a limited number of flights to study ozone and PM formation in the region around Atlanta, Ga. Atlanta is a much larger city than Nashville, with proportionally greater air pollution emissions. A major contributor to Atlanta's ozone problem is automobile exhaust, which plays a significant role in particulate matter production. NOAA's P-3 aircraft will gather data, during extensive low-altitude flight patterns (about 1500 feet above the ground) over the major population and air traffic centers of Nashville and Atlanta, that permits scientists to assess the similarities and differences in the air quality of these two southern cities and allow policy-makers to determine the appropriate response to air quality management.

Scientists hope to maximize their findings by conducting the experiments in both cities and to provide a regional perspective for the atmospheric process studies. According to Meagher, "We're expecting to develop a really good database from these experiments that will provide the sound science needed to find solutions to the special air pollution problems facing this region."

For more information concerning SOS, check the Aeronomy Lab web site at: www.al.noaa.gov