UAM-V® Photochemical Modeling System
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This section provides users-only information about the continuing development of UAM-V®.

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December 4, 2002

An Updated Photochemical Mechanism for Modeling Urban and Regional Air Quality: Carbon Bond, Version 5 (CB-V)


The latest Carbon Bond mechanism, Version 5 (CB-V), is now ready for use. CB-V is another step in the progressive development of the carbon-bond approach for producing "economical" yet comprehensive chemical mechanisms for simulating the formation of secondary atmospheric pollutants. This latest version, without significantly impacting computer resources or previously completed ozone attainment demonstrations, updates and expands the reactions contained in the extensively applied CB-IV mechanism by drawing on the latest evaluations of atmospheric reactions. CB-V provides a scientifically current treatment of the atmospheric chemistry that governs, for any seasonal condition and continental location, the formation of ozone (and other oxidants), the inorganic and organic constituents of fine particles, and air toxicants as well as the deposition of acidic and toxic substances. CB-V is designed to address the effects of precursor air emissions on ozone, PM, air toxics, visibility, acid deposition and water quality. Additionally, CB-V retains the unique Carbon Bond features of carbon mass balance and the ability to consistently handle a wide variety of organic molecules.

In the remainder of this technical memorandum, we first present highlights of the considerations that led to CB-V, the process followed for its development and some of its key features. The memorandum then documents the evolution of CB-V, starting with the changes made to CB-IV and concluding with a tabular summary of the 120 reactions that comprise CB-V. The memorandum concludes with a summary of results obtained using CB-V in UAM-V for an ozone simulation of a 14-state southeast region over a 9-day period (September 10-18, 1997).

Click for full document: CB5_SAI_Memo_021204.doc [757 KB]