OZIPR Model

The OZIPR model is described in Appendix III. It is a box model that has comprehensive chemical submodels that lump organics in two different ways. It allows for variation of meteorology through time-dependent mixing heights, temperatures, etc. 

Because the oxidants for S02 are generated in the VOC-NO. system discussed in Chapter 6, the overall gas-phase mechanism for the oxidation of S02 to h2so4 is quite complex. The reader is referred to the mechanism in the RADM model (Regional zlcid Deposition Model) for a treatment of the VOC-NO -S02 chemistry (Stockwell et al., 1990 Gao et al., 1996). It should be noted that an earlier version of this mechanism is given in some of the examples included with the OZIPR model discussed in Chapter 16 and whose applications are included with this book. 

The RADM mechanism is found in examples of the OZIPR model whose applications are used in this book (see problems at end of chapter). 

The EPA s OZIPR model (Ozone Isopleth Plotting Program, Research Version) was designed to be used primarily for calculating emissions reductions needed to reach the NAAQS for 03. Both DOS-based and Windows versions are available and can be downloaded from the Web site http //www.academicpress.com/ pecs/download... 

OZIPR contains two comprehensive chemical mechanisms that use two different approaches to lumping organics. The two mechanisms used in these models, the RADM (Regional Acid Deposition Model) and the Carbon Bond Mechanism (CBM), are discussed in Chapter 16.A.3b and in detail by Stockwell et al. [J. Geophys. Res., 95, 16343 (1990) and J. Geophys. Res., 102, 25847 (1997)] and by Gery et al. [J. Geophys. Res., 94, 12925 (1989)]. 

Michael Gery, who developed the OZIPR model, graciously provided advice on its use as well as electronic copies of the documentation. This model, which contains the two major chemical mechanism schemes for gas-phase, VOC-NC/ chemistry in use in atmospheric chemistry, is available on the Academic Press Web site (http //www.academicpress.com/pecs/down-load). A number of problems using this model are included in the book, and it is a valuable teaching tool for assessing the effects of various model input parameters on predicted concentrations of a wide variety of gas-phase species. His assistance and that of Marcia Dodge of the U.S. EPA in making it available are appreciated. 

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