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Adding new SOA tracers to chemical mechanism?

A

aberg

New Member
I have added SOA tracers to the model by modifying the chemical mechanism, adding reactions of specific monoterpenes with OH and O3, e.g.:

BPIN + OH -> 0.31*SOAPI + OH ; 7.89E-11

(In this case BPIN points to the beta-pinene emissions from CLM, the OH is recycled since b-pinene is already included in C10H16 and we don't want to consume the OH twice, 0.31 is the bulk SOA yield, and I defined BPIN -> C10H16 and SOAPI -> C12 in the solutions list so they'd have the correct molecular weights). I successfully ran the pre-processor with these changes and it output 14 modified .F90 files, and have successfully run the model getting output for the SOA tracers.

My question is, since I'm adding new SOA tracers, I need to know where to make further changes/additions in the code (e.g. dry deposition, and I think that photolysis rates depend on aerosol loading?). I want to make sure I'm not missing anything and that my new SOA tracers are dealt with properly in the model.

Thanks! Let me know if you need any more information. (I am running CAM with MEGAN: cesm1_1_beta05_megan02, compset F_SD_CAMCHEM without CN).
 
F

fvitt

CSEG and Liaisons
Staff member
A new SOA scheme has been added to CAM-Chem in CAM version cam5_1_23
(chem pkg trop_mozart_soa), CESM tag cesm1_1_alpha12a (compset FMOZSOA)

For wet deposition (wash out) of new gas-phase species modify the following code:

models/atm/cam/src/chemistry/mozart/mo_sethet.F90

For dry deposition of new species (gas-phase and aerosol-phase)
appropriate code will need to be added to:

models/atm/cam/src/chemistry/mozart/mo_drydep.F90 (over ocean)
models/drv/shr/seq_drydep_mod.F90
models/lnd/clm/src/biogeochem/DryDepVelocity.F90 (over land)

You may need to modify mo_setsoa.F90 for your new SOA scheme

For CAM build-namelist to generate appropriate wet-dep and dry-dep lists for
the addition species do the following:

add new aerosol-phase species to
models/atm/cam/bld/namelist_files/master_drydep_list.xml
models/atm/cam/bld/namelist_files/master_aer_wetdep_list.xml

add new gas-phase species to
models/atm/cam/bld/namelist_files/master_drydep_list.xml
models/atm/cam/bld/namelist_files/master_gas_wetdep_list.xml
 
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