How to revise the stoichiometric coefficient in CMAQ CB06 mechanism

CMAQ Chemistry and Aerosols
1

Hi, I am using CMAQ5.1 and CMAQ5.3 with the Carbon Bond mechanism (CB05 or CB6)
I want to revise the stoichiometric coefficient of some gas-phase reactions. For example, the reaction in mech_cb6r3_ae7_aq.def is,
FORM = 2.0*HO2 + CO

Now, I want to change the stoichiometric coefficient, 2.0, to 0,
FORM = 0*HO2 + CO

how should I edit the code? I find there is a number set of SC in RXNS_DATA_MODULE.F90, but I dont know which one is related to the reaction R97? How should I revise the code? Please show some guidance to me.

./RXNS_DATA_MODULE.F90:! SC = Stoichiometric coefficients
./RXNS_DATA_MODULE.F90: REAL( 8 ) :: SC( NRXNS,MXPRD )
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 1 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 2 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 3 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 4 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 5 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 6 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 7 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 8 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 9 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 10 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 11 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 12 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 13 ), IRXXN = 1, NRXNS ) / &
./RXNS_DATA_MODULE.F90: DATA ( SC( IRXXN, 14 ), IRXXN = 1, NRXNS ) / &

1 Like
2

I just noticed that this may have been solved in this issue: How to close a certain gas-phase reaction in CMAQ5.1? - #5 by wangnan

3

To add to the response from @lizadams and the suggested thread, we do not recommend modifying the SC array in the RXNS_DATA_MODULE.F90 file and the relevant EBI solver file as mistakes can easily be made.

The recommended approach is to use the chemmech and create_ebi tools/utilities to create new mechanism module files and ebi solver. Versions 5.1 and 5.3 have these programs under the tools or UTIL directory, respectively.

3 Likes