A Research Program On Tropospheric Ozone
As discussed in this report, the scientific information used to develop regulations to control ozone is inadequate in many cases. It is difficult to predict accurately how ozone concentrations will respond to reductions in precursor emissions. It is also difficult to predict the effect of changes in atmospheric trace gas concentrations or climate on tropospheric ozone. A coherent and focused national research program with a long-term perspective is needed to provide government agencies with a better understanding of tropospheric ozone formation, transport, and accumulation. Progress toward reducing ozone concentrations in the United States has been severely hampered by the lack of such a program. This chapter addresses the need for a coordinated national research program directed at elucidating the chemical, physical, and meteorological processes that control ozone formation and concentrations over North America. The establishment of the North American Consortium for Atmospheric Modeling of Regional Air Quality (through a memorandum of understanding among more than a dozen funding agencies) represents an important step in coordinating research, but it does not answer the need for a focused research program directed from one program office.
A good analogy for the research program needed is the U.S. effort to address depletion of the stratospheric ozone layer by chlorofluorocarbons.1 For this program, EPA is the relevant regulatory agency, but NASA's Upper
1This program is discussed as an example of one with many features that would be desirable in a tropospheric ozone research program. The committee does not recommend which agency should direct such a program.
Atmosphere Research Program is directed to ''continue programs of research, technology, and monitoring of the phenomena of the stratosphere for the purpose of understanding the physics and chemistry of the stratosphere and for the early detection of potentially harmful changes in the ozone of the stratosphere'' (Public Law 95-95, Clean Air Act Amendments, 1977). The partnership has worked well, and the basic research program has prepared the scientific foundation for international assessment (WMO, 1986, 1988, 1990) and for the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer (1987). NASA has developed a basic research program of laboratory and field measurements, satellite data analysis, and theoretical modeling. The particular strengths of the program have been its broad participation base, which includes academic, government, industrial, and contract research groups, and its careful coordination with other federal and industrial programs and non-U.S. research efforts. The results of this comprehensive and coordinated research effort have been reported to Congress and to EPA. Its scientific assessments often include specific modeling studies that meet the regulatory and policy needs of EPA. A similar partnership that meets the needs of the research community and those of the regulatory agency will be necessary to establish a reliable scientific basis for the improvement of this nation's air quality.
The committee therefore recommends that a coordinated national program be established for the study of tropospheric ozone and for other related aspects of air quality in North America. This program should include coordinated field measurements, laboratory studies, and numerical modeling that will lead to a better predictive capability. In particular, it should elucidate the response of ambient ozone concentrations to possible regulatory actions or to natural changes in atmospheric composition or climate. To avoid conflict between the long-term planning essential for scientific research and the immediacy of requirements imposed on regulatory agencies, the research program should be managed independently of the EPA office that develops regulations under the Clean Air Act or other government offices that develop regulations. The research program must have a long-term commitment to fund research on tropospheric ozone. The direction and goals of this fundamental research program should not be subjected to short-term perturbations or other influences arising from ongoing debates over policy strategies and regulatory issues. The program should also be broadly based to draw on the best atmospheric scientists available in the nation's academic, government, industrial, and contract research laboratories. Further, the national program should foster international exchange and scientific evaluations of global tropospheric ozone and its importance in atmospheric chemistry and climate change. The recommended tropospheric ozone research program should be carefully coor-
dinated with the Global Tropospheric Chemistry Program (UCAR, 1986) currently funded and coordinated by the National Science Foundation (NSF), and corresponding global change programs in the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), the Department of Energy (DoE), and others.