SAPRC-07 Mechanism and Emissions Assignment Files

This page is for the mechanism implementation and testing files for various versions of the SAPRC-07 mechanisms. Mechanism definition files are currently available for the CMAQ and SAPRC modeling systems. Click here for the page to download all the files and programs to implement the mechanism using the SAPRC box and chamber modeling software.

Please note: Several errors were found in the SAPRC-07 mechanisms, including one that has small but non negligible effects on ozone and other predictions. The documentation and files implementing the mechanism have been updated. Please replace all documentation reports and files dated prior to January 25, 2010.

What's new (changes after August 27, 2008)

12/15/11: Emissions assignments were updated for RACM2 and CB05 and a few other assignments were corrected (see the Speciation Databas e page).
3/31/10: Several corrections made to the emissions assignments (see below and Speciation Databas e page).
1/28/10: An error in the files implementing the mechanism that caused in the rate constant for the O1D+H2O reaction to be low by ~18% was found and corrected. This resulted in slightly increased O3 predictions in ambient simulations, though still lower than calculated using SAPRC-99. All versions of the mechanism are affected. The mechanism implementation files have been updated to incorporate this correction.
1/22/10: A minor error in the procedure used to output.MEC files where the "N" parameter in falloff reactions was not being given when it was different than 1.0 was corrected. This affects only the files for CMAQ and not the calculations using the SAPRC software, which are the basis of the calculations and reactivity tables in the reports.
1/15/10: A number of errors were found in the base SAPRC-07 mechanism and corrected, and the reactivity scales, documentation, and files have been updated accordingly. A number of edits were also made to the documentation not only to correct the errors but to make editorial changes and corrections noticed as part of preparing journal articles documenting the mechanisms. The corrections and updates are described in Appendix E in the SAPRC-07 documentation report. Most of the errors concern low NOx reactions that do not significantly affect O3 predictions, though an error was found that affected MIR values for tertiary amines. The changes affect all versions of the mechanism, and all files and reports downloaded prior to this date should be replaced by the current versions.
11/13/09: Minor errors in the "C" versions of the mechanisms are corrected. (This is the version that uses explicit reactions for peroxy radical operators to be consistent with most airshed model software. The correction involved adding 0.5 PROD to reactions of the xPROD operator with MEO2, RO2C, and RO2XC, for consistency with the treatment of these reactions in the "B" version. The effect on most model simulations should be negligible.)
7/28/09: The mechanism definition file for implementing SAPRC-07A in CMAQ has been added.
4/9/09: Files for implementing the mechanisms using the SAPRC software, available at the SAPRC mechanism file page, and the condensed mechanism report, have been updated to the current mechanism version.
4/8/09: The mechanism implementation files affected by the recent revisions to the SAPRC-07 mechanisms have now been updated. The current version of the mechanism is dated 4/8/09. The emissions processing, photolysis, and VOC lumping assignment files are not affected.
12/17/08: The final report documenting the condensed SAPRC-07 mechanisms is now available on the SAPRC mechanism page. Note that report has not yet been updated to reflect the changes to the mechanism made after July, 2008. An updated version of this report should be made available sometime in April, 2009.
SPEC4ASN.CSV was updated to include new Speciate 4.2 categories
Photolysis data for glycolaldehyde, needed for SAPRC07T, added to PHF.ZIP.

Mechanism Definition Files (MEC = CMAQ format, RXN = SAPRC format)

File(s)	Date	Mechanism Version
SAPRC07B.MEC SAPRC07B.RXN	1/25/10	Standard version of the SAPRC-07 mechanism as documented in the CARB report, using chemical operators for peroxy radicals to reduce the number of reactions (CMAQ version is not compatible with the current versions of the CMAQ chemical compiler)
SAPRC07C.MEC SAPRC07C.RXN	1/25/10	The "expanded" version of the above mechanism. Same chemistry, predictions and emissions assignments as SAPRC07B.MEC, and SAPRC07B.RXN, but uses additional reactions for the peroxy radicals so that the .MEC version is compatible with current versions of CMAQ chemical compilers.
SAPRC07A.MEC SAPRC07A.RXN	1/25/10	The version of SAPRC-07 that uses the condensed peroxy radical operator representation as used in SAPRC-99. Discussed in the report documenting the condensed SAPRC-07 mechanisms. (See also the main SAPRC mechanism web page.)
S07TB.MEC S07TB.RXN	1/25/10	"Toxics" version of SAPRC-07, with additional model species to explicitly represent selected toxics species. This is referred to as "SAPRC07T" in the emissions assignment files. This version uses chemical operators for peroxy radicals to reduce the number of reactions (.MEC not compatible with current versions of CMAQ chemical compiler) (Revised 4/8/09)
S07TC.MEC S07TC.RXN	1/25/10	The "expanded" version of the above mechanism. Same chemistry, predictions and emissions assignments as S07TB.MEC, but uses additional reactions for the peroxy radicals so it is compatible with current versions of CMAQ chemical compilers.
CS07A.MEC CS07A.RXN	1/52/10	The standard condensed SAPRC-07 mechanism using the SAPRC-99 peroxy radical representation. This is the most condensed version considered appropriate for airshed model calculations. Discussed in the report documenting the condensed SAPRC-07 mechanisms. (See also the main SAPRC mechanism web page.)
CS07B.MEC CS07B.RXN	1/25/10	The version of the condensed SAPRC-07 mechanism that uses the more detailed SAPRC-07 peroxy radical representation. This may be more appropriate for applications requiring better hydroperoxide predictions. Discussed in the report documenting the condensed SAPRC-07 mechanisms. (See also the main SAPRC mechanism web page.)

Other files needed or useful for mechanism implementation

File(s)	Date	Description
PHF.ZIP	10/29/08	Set of photolysis (PHF) files with absorption cross-section and quantum yield data for all the photolysis rates in the mechanisms. (Includes all those needed for standard and condensed SAPRC-07, and also the additional photolysis files needed for SAPRC07T.
Photks.xls	2/2/10	Photolysis rates need for all versions of SAPRC07 calculated for the set of actinic fluxes used in the reactivity scale calculations. The actinic fluxes were provided in 1991 by Harvey Jeffries for Summer conditions at 540 meters, and are included in the spreadsheet. Parameters fitting the photolysis rates as a function of zenith angle (using the parameterization used in the MCM mechanism) are also included.
S07CHK.XLS CS07CHK.XLS S07TCHK.XLS	1/25/10	Excel files containing inputs and outputs for test calculations for checking implementation of the standard (S07), condensed (CS07), and "toxics" (S07T) versions of the SAPRC07 mechanisms. The sheet "Input" has the initial concentrations and photolysis rate values for this static, no dilution, no emission calculation. The concentration units are ppm and the time units are minutes. The calculation goes for 720 minutes and results are output each 15 minutes. Each of the active model species has non-zero values during the simulation. For the standard and "toxics" versions of the mechansim, the sheets "Version B" and "Version C" have the results for the species for the two methods for implementing the peroxy radical operators, and show that essentially the same results. For the condensed mechanisms, the sheets "CS07A" and "CS07B" show the results for the two different versions, For all versions, the "Species" sheet summarizes the average concentrations of the species. (Revised 4/8/09)
saprc07.pdf saprc07.doc saprc07.xls	1/27/10	Report documenting the standard SAPRC07 mechanism, including listings of species reactions in the mechanism. The PDF and DOC files contains the text of the report excluding the largest tables in the appendices and the XLS file contains all the large tables in the appendices.
csaprc07.pdf csaprc07.doc	1/28/10	Report documenting the condensed SAPRC07 mechanisms, including listings of species and reactions in the mechanisms.
SAPRC07T.XLS	1/25/10	This Excel file lists the species in the mechanism and the reactions in both the "B" and "C" versions of the SAPRC07T mechanism. It also has a description of the compounds and indicates the names for the compounds represented in the emissions, which in some cases are different (shorter) than the names used in the mechanism. Presently there is no report documenting this version of the mechanim, beyond the documentation of the standard mechanism given above. (Revised 4/8/09)

Emissions input assignments for the Speciation Tool (using Speciate version 4 chemical categories). See the Speciation Database web site for the inputs in other formats and further information.

File(s)	Date	Mechanism Version
MECHLIST.CSV	12/15/11	Listing of the mechanisms for which assignments are made. Includes SAPRC07 (for SAPRC07B.MEC or SAPRC07C.MEC), SAPRC07T (for S07TB.MEC or S07TC.MEC) and CS07 (for CS07A.MEC). Also includes SAPRC99, CBIV, CB05, and RACM2).
MSCLIST.CSV	12/15/11	List of model species used for emissions in each of the mechanisms listed in MECHLIST.CSV.
SPEC4ASN.CSV	12/15/11	Assignments of all of the Speciate 4.2 chemical categories to the model species listed in MSCLIST.CSV for the mechanisms listed in MECHLIST.CSV.

Files for implementing the SAPRC-07 mechanism using the SAPRC model simulation software, with test and chamber simulations using this software, are available at the SAPRC mechanism software files page.

SAPRC-07 Chemical Mechanism and Emissions Assignment Files

What's new (changes after August 27, 2008)

Mechanism Definition Files (MEC = CMAQ format, RXN = SAPRC format)

Other files needed or useful for mechanism implementation

Emissions input assignments for the Speciation Tool (using Speciate version 4 chemical categories). See the Speciation Database web site for the inputs in other formats and further information.

Files for implementing the SAPRC-07 mechanism using the SAPRC model simulation software, with test and chamber simulations using this software, are available at the SAPRC mechanism software files page.

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