B.S. (Physics), 1962, University of Illinois (Urbana)
M.S. (Physics), 1964, University of California (Berkeley)
M.A. (Mathematics), 1967, University of California (Berkeley)
Ph.D. (Applied Mathematics and Statistics), 1972, State University of New York
at Stony Brook
Research Interests:
Urban-and regional-scale air pollution; atmospheric chemistry;
development, evaluation and application of air quality models; numerical
computational techniques; global chemistry and climate; multi-scale coupling of
atmospheric chemical transport processes; acid deposition; stratospheric
chemistry.
Air quality modeling is a multidisciplinary system analysis approach to the study of the environment. An inescapable byproduct of human evolution is our ever increasing ability to pollute our own environment. Ever since the beginning of industrial revolution man has introduced into the atmosphere uncountable variety of pollutants with wide ranging impact on the environment. Air pollution, while mostly invisible, has far-reaching consequences. Urban- and regional-scale oxidants affect our health and physical surrounding. Acid deposition or acid rain damages our forests and aquatic system. Stratospheric ozone destruction affects the whole ecosystem with potentially devastating climatic consequences. The ever increasing release of carbon dioxide and other selected long-lived trace chemicals is changing the climate of our planet. These and other environmental issues or problems are vast and complex. Computational modeling has become an essential tool in our effort to understand the delicate balance among the trace chemicals in the atmosphere.
Our research is directed toward the development, evaluation and application of comprehensive modeling system of atmospheric chemistry and transport. While atmospheric measurements tell us much about the atmosphere, because of both technical and operational limitations they provide only limited but strategic coverage. Further, they represent only the present not what may be or what will be the state of the environment some years from now. To conduct actual atmospheric experiment on changing the environment so that we may study the potential consequences is much too intrusive and perturbing to the society. Comprehensive theoretical models is the most logical and useful tool to assist in the analysis of existing data, to plan for new field experiments, to conduct "what-if" experiments and to assess the consequences of regulatory actions.
Since atmospheric pollution occurs on many geographic and temporal scales, we are interested not only in the analysis of air quality on the urban-, regional- and global-scales but also the multi-scale coupling among them. We have developed a set of comprehensive three-dimensional coupled transport and chemistry models. These models describe the emission, transport, transformation and deposition of over 40 chemical species from natural and anthropogenic origins. These models were developed for applications to urban, regional and global pollution studies. We are now interested in nesting these models so that between every adjoining pair in scales the smaller model can provide subgrid details to the smaller model. In the absence of such across-scale coupling it is very difficult to obtain the needed boundary and initial conditions for the urban and regional models.
These models in addition to serving as assessment tools and system analysis tools also are natural reference platforms for studying better descriptions of individual processes such as gas-phase chemistry, aqueous chemistry, cloud mixing, boundary layer processes, wet and dry depositions and coupling to meteorological processes. Because these models need to be both accurate and efficient, continued advances in computational techniques must be maintained. Model evaluation is another critical component of our research in that a useful model must "give the correct results for the right reason".
Selected Publications
The RAMD2.0 chemical mechanisms for regional air quality modeling." W.R. Stockwell, P. Middleton, J.S. Chang and X. Tang. J. Geophys. Res. 95: 16343-16367, 1990.
"A Nested grid mesoscale atmospheric chemistry model," J. Pleim, J.S. Chang and K. Zhang, J. Geophys. Res. 96: 3065-3084, 1991.
The Regional Acid Deposition Model and Engineering Model, J.S. Chang, P.B. Middleton, W.R. Stockwell, C.J. Walcek, J.E. Pielm, H.H. Lansford, S. Madronich, F.S. Binkowski, N.L. Seaman, D.R. Stauffer, D. Byun, J.N. McHenry, H. Hass and P.J. Samson, NAPAPSOS/T Report 4, 1991.
"A three-dimensional numerical model of cloud dynamics, microphysics and chemistry I: concepts and formulation," C. Wang and J.S. Chang, J. Geophys. Res. 98: 14827-14844, 1993.
"A three-dimensional numerical model of cloud dynamics, microphysics of a severe local storm," C. Wang and J.S. Chang, J. Geophys. Res. 98 14845-14862, 1993.
"A three-dimensional numerical model of cloud dynamics, microphysics and chemistry III: redistribution features of pollutants," C. Wang and J.S. Chang, J. Geophys. Res. 98: 16787-16798, 1993.
"A three-dimensional numerical model of cloud dynamics, microphysics and chemistry IV: cloud chemistry and precipitation chemistry," C. Wang and J.S. Chang, J. Geophys. Res. 98: 16799-16808, 1993.