This has been superseded by the SAPRC-99 Mechanism

See /~carter/reactdat.htm


Updated SAPRC-97 Mechanism

William P. L. Carter
Research Chemist
Air Pollution Research Center, and
College of Engineering, Center for Environmental Research and Technology
University of California, Riverside, CA 92621

Phone: (909) 781-5797
Fax: (909) 781-5790
e-mail: carter@cert.ucr.edu
Home Page

This FTP Directory contains the most updated versions of the SAPRC or Carter mechanisms which are available for general distribution. This is the version of the mechanism which is documented in the report of Carter et al. (1997) Because this mechanism was finalized in 1997, it can be referred to as the "SAPRC-97" mechanism. This is an update of the "SAPRC-93" mechanism which was used in the Carter et al (1995) paper. (The files for the SAPRC-93 mechanism can also be downloaded by FTP.) The main difference between SAPRC-97 and SAPRC-93 concerns the reactions of the aromatics, which were revised based on results of new chamber data. This mechanism accounts for observed differences in reactivities of aromatic isomers which were previously assumed to have similar mechanisms, and predicts higher reactivities for most aromatics to better fit experiments using a xenon arc light source. This isoprene mechanisms are the same as distributed with the SAPRC-93 mechanism, as discussed in the papers of Carter and Atkinson (1996) and Carter (1996).

The files included are those needed to implement this mechanism in the FCM version of the UAM which was developed at STI ("Development of the Flexible Chemical Mechanism Version of the Urban Airshed Model," N. Kumar, F. W. Lurmann, and W. P. L. Carter, Report to California Air Resources Board, Agreement no. 93-716. Document No. STI-94470-1508-FR, Sonoma Technology, Inc. Santa Rosa, CA, August, 1995.) However, the mechanism files should also be in the same format as needed for the CALGRID model, and the PREPCOMP emissions pre-processing for the FCM include the .SAR files needed for CALGRID emissions processing. See also Carter (1988) for a detailed discussion of the mechanism preparation and emissions processing programs. Updates and modifications to those programs made since then are summarized in the Kumar et al. report, cited above.] The updated emissions processing software for FCM and CALGRID can be obtained by FTP.

Listing of Files


 
 
File  Description 

Chemical Mechanism files
SAPRC97.RXN  SAPRC-97 general mechanism (without isoprene chemistry)
ISOP-1.RXN  The most condensed (one product) version of the isoprene mechanism. This is the default because it should perform satisfactorily except for applications where isoprene product predictions are required. Requires SAPRC97.RXN or equivalent.
ISOP-4.RXN  This is the four product condensed version of the isoprene mechanism which can be used when methacrolein and MVK predictions are desired. Requires SAPRC97.RXN or equivalent. (Edit SAPRC97.PRP as indicated in the comments there to use it.)
ISOP-D.RXN  This is the detailed isoprene mechanism as documented by Carter and Atkinson (1996). Requires SAPRC97.RXN or equivalent. (Edit SAPRC97.PRP as indicated in the comments there to use it.)
*.PHF  Photolysis absorption cross section and quantum yields used. (See, for example, NO2.PHF.
SAPRC97.LPC  Lumping control file for SAPRC-97 mechanism for airshed models. (Two lumped alkanes, two lumped aromatics, ethene explicit, two lumped higher non-biogenic alkenes, isoprene explicit, one lumped terpene.)
ALKOTH.GEN  Mechanistic parameters for alkanes and other compounds which are lumped with alkanes, such as alcohols, etc.
AROMATIC.GEN  Mechanistic parameters for aromatics
ALKENEA.GEN  Mechanistic parameters for alkenes except for isoprene and terpenes
ALKENET.GEN  Mechanistic parameters for terpenes
LUMPMOLE.LPM  Lumped molecule assignments of applicable detailed model species.

Other Mechanism Preparation Input Files (compatible with FCM)
SAPRC97.PRP  Main mechanism preparation file for FCM, using SAPRC97.RXN, ISOP- *.RXN, and the *.PHF files. As distributed it specifies use of the one product condensed isoprene mechanism, but can be edited to use another alternative. See comments in the file.
DUMMY.RXN  Specifies parameters output by emissions processing program which are ignored in the mechanism. Used by SAPRC97.PRP.

Other Emissions Assignment input files
DMS.PRM  Lists and gives molecular weights, carbon numbers, and other information about all detailed model species used when processing emissions.
SAROAD.PRM  Assigns detailed model species to emissions classified using SAROAD numbers.
OLDNAMES.LPM  Renames detailed model species in older profiles to be consistent with nomenclature system currently used by mechanism parameter files.

Input files used by FCM processing example. (See Kumar et al., 1995)
PREPUAM.INP  List of file names and options used by all FCM programs.
LA082787.EMI  Example emissions profile (mass emissions of species identified by SAROAD numbers from the August, 27, 1987 SCAQS episode.)
STDZA640.JZS  Actinic flux data as computed by Jeffries and used in scenarios for calculating reactivity scales. Needed by PREPUAM to compute photolysis rates as a function of zenith angle from PREP output.
PETERSON.JZS  Actinic flux data as given by Peterson. Most similar to that probably used to derive photolysis rates for the UAM. Can be used as an alternative to STDZA640.JZS by changing the JZS reference in PREPUAM.INP.
RESIST.DAT  Used by PREPUAM to provide UAM with surface resistance values for the model species. Mechanism and scenario dependent.

Output files for FCM example: PREP output:
SAPRC97.MOD  Mechanism data file
SAPRC97.PRO  Mechanism listing file
SAPRC97.F  Mechanism-dependent subroutine to be linked with the airshed model.
CONSTR.F  Parameter initialization subroutine to be linked with PREPUAM. (Not supported in this version, and should contain no executable code. This is output for future compatibility.)

Output files for FCM example: Emissions pre-processing output:
TESTLA.CMP  Emissions data in LA082787.EMI given as molar emissions of detailed model species. Produced by EMITOCMP. Can be used as input to PREPCOMP to define parameters for lumped model species (e.g., ALK1, OLE1, etc.)
ARBROG.CMP  Ambient reactive organic gas (ROG) emissions composition which was used to define the base ROG mixture (emissions of ROG's from all sources) in the reactivity calculations of Carter (1994). Also be used as input to PREPCOMP as an alternative for defining parameters for lumped model species.
TESTLA.RXP ARBROG.RXP  Mechanistic parameters optimized for the corresponding mixture. Output by PREPCOMP and needed as input to PREPUAM to compute the emissions-dependent parameters needed by the model. Also used as input to CALGRID model for this purpose.
TESTLA.SAR ARBROG.SAR  Assignments of SAROAD emissions classes to lumped species in the model corresponding to the particular mixture. Should be compatible with the emissions processing routines developed for the CALGRID model, but this needs to be verified.

Output files for FCM example: PREPUAM output:
CHEMOUT  Mechanism and parameter listing output.
BLCKDATA.F  One of three mechanistic dependent specification FORTRAN files which should be linked with the FCM/UAM model.
CHDATA.CMD  As above
CHPARM.CMD  As above
CHEMPARM  Chemical parameter input used by the FCM/UAM model.

Other files of potential interest
ALKOTH.RXN
ALKENET.RXNALKENEA.RXN
AROMATIC.RXN
These files, which are not needed for normal applications of the SAPRC-97 mechanism, have the reactions of the normally lumped detailed model species in a format compatible with the PREP program. The parameters for these species are in the corresponding .GEN file. These files are included for those who may wish to modify the mechanism to represent reactions of some of these species explicitly, without using the variable parameter method.
TESTLA.RXN
ARBROG.RXN
These files, which are also not needed for normal applications of the SAPRC-97 mechanism, have the reactions of the model species used to represent the lumped alkanes, aromatics, and alkenes whose parameters are optimized for either the TESTLA.CMP or the ARBROG.CMP mixture in a format compatible with the PREP program. These can be used as a replacement for the reactions of the ALK1, ALK2, ARO1, ARO2, OLE1, and OLE2 species in applications where a more appropriate composition is not available or unknown, or in modeling systems where programs such as PREPCOMP are incompatible or not available. These files are included for those who cannot use PREPCOMP and wish to use the mechanism as a fixed parameter lumped mechanism. The user should chose whether the emissions-based TESTLA or the air-quality-based ARBROG composition is the most appropriate for the application in question.

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Last Modified by William P. L. Carter March 16, 1998 (Superseded notice added 9/12/00)