Zero organic carbon (OC) concentration in WRF-Chem output (SAPRC99/MOSAIC)

[neyestani]

Hi there,

I'm running WRF-Chem with SAPRC99 and MOSAIC chemistry options (chem_opt=198). I have anthropogenic (wrfchemi*) and biomass burning (wrffirechemi*) emission inputs.
WRF-chem output shows concentrations for gas and aerosol species except for organic carbon aerosols (oc_a0*). I checked the input files. there are OC emissions from both anthropogenic and biomass burning. Also, in WRF-Chem output, OC emission (ebu_oc) has reasonable values.

Does anyone know why my OC concentration is zero in WRF-Chem output? Below are some related lines from the namelist.

&time_control
auxinput5_inname = 'wrfchemi_d<domain>_<date>',
auxinput7_inname = 'wrffirechemi_d<domain>_<date>',
auxinput5_interval_m = 60, 60, 60,
auxinput7_interval_m = 60, 60, 60,
io_form_auxinput5 = 2,
io_form_auxinput7 = 2,
frames_per_auxinput5 = 1, 1, 1,
frames_per_auxinput7 = 1, 1, 1,
&chem
kemit = 8,
chem_opt = 198, 201,
bioemdt = 12., 4.,
photdt = 12., 4.,
chemdt = 12., 4.,
io_style_emissions = 2,
emiss_inpt_opt = 102, 102,
emiss_opt = 13, 10,
chem_in_opt = 1, 0,
phot_opt = 3, 3,
gas_drydep_opt = 1, 1,
aer_drydep_opt = 1, 1,
bio_emiss_opt = 0, 0,
dust_opt = 0,
dmsemis_opt = 0,
seas_opt = 0,
aer_op_opt = 1,
opt_pars_out = 1,
gas_bc_opt = 1, 1,
gas_ic_opt = 1, 1,
aer_bc_opt = 1, 1,
aer_ic_opt = 1, 1,
gaschem_onoff = 1, 1,
aerchem_onoff = 1, 1,
wetscav_onoff = 0, 0,
cldchem_onoff = 0, 0,
vertmix_onoff = 1, 1,
chem_conv_tr = 0, 0,
biomass_burn_opt = 1, 2,
plumerisefire_frq = 12,
aer_ra_feedback = 1, 1,
have_bcs_chem = .false., .false.,

Thank you,
Soroush

 

[jordanschnell]

Hi Soroush,

This looks to be an intended feature of the MOSAIC mechanisms with VBS, though I do not know much more about it. See lines in module_mosaic_addemiss.F:

chem_select_1 : SELECT CASE( config_flags%chem_opt )

CASE(SAPRC99_MOSAIC_4BIN_VBS2_KPP, SAPRC99_MOSAIC_8BIN_VBS2_AQ_KPP, &

SAPRC99_MOSAIC_8BIN_VBS2_KPP)!BSINGH(12/04/2013): Added SAPRC 8 bin and non-aq on 04/03/2014! Set the oc to zero for VBS

aem_oc = 0.0

END SELECT chem_select_1


chem_select_3 : SELECT CASE( config_flags%chem_opt )


CASE(SAPRC99_MOSAIC_4BIN_VBS2_KPP) ! Set the oc to zero for VBS


aem_oc = 0.0


END SELECT chem_select_3


Jordan