User:Jmandel/chem
Tracer accessed as grid%tracer(i,k,j,p_smoke) real,intent(inout),dimension( ims:ime,kms:kme,jms:jme,num_tracer ) :: tracer
from use module_state_description , only: num_tracer, p_smoke
which has INTEGER, PARAMETER :: tracer_smoke = 1
similar code in chem/module_add_emiss_burn.F: chem(i,k,j,p_smoke) = chem(i,k,j,p_smoke)+ebu(i,k,j,p_ebu_co)*conv_rho
defined in ./inc/scalar_indices.inc: P_smoke = 1 ; F_smoke = .FALSE.
from registry.chem: package radm2sorg chem_opt==2 - chem:so2,sulf,no2,no,o3,hno3,h2o2,ald,hcho,op1,op2,paa,ora1,ora2,nh3,n2o5,no3,pan,hc3,hc5,hc8,eth,co,ol2,olt,oli,tol,xyl,aco3,tpan,hono,hno4,ket,gly,mgly,dcb,onit,csl,iso,hcl,ho,ho2,so4aj,so4ai,nh4aj,nh4ai,no3aj,no3ai,naaj,naai,claj,clai,orgaro1j,orgaro1i,orgaro2j,orgaro2i,orgalk1j,orgalk1i,orgole1j,orgole1i,orgba1j,orgba1i,orgba2j,orgba2i,orgba3j,orgba3i,orgba4j,orgba4i,orgpaj,orgpai,ecj,eci,p25j,p25i,antha,seas,soila,nu0,ac0,corn
state real so2 ikjftb chem 1 - i0{12}rhusdf=(bdy_interp:dt) "so2" "SO2 concentration" "ppmv"
Call chain: chem_driver.F -> emissions_driver.F -> add_emiss_burn.F, plumerise_driver -> plumerise module_emissions_anthropogenics
gas emissions are converted to the concentration changes in module_emissions_anthropogenics.F located in WRFV3/chem. Basically, since each gas occupies the same volume under the same P and T, all gass species are converted from mole/km2h to delta ppmv (which is 1E6 times mixing ratio in mole/mole) in the same way.
The conversion looks like that:
E is emission [mole/(km^2 hr)]
conv_rho is converted emission in ppmv [-]
rho_phy(i,jk) is air density [kg/m3}
dz8w(i,j,k) is vertical grid spacing for the lowest model layer [m]
dtstep is model time step [s]
8.047e-6 is conversion factor – km^2 hr to m^2 s (2.7778e-10) * molecular mass of air 0.02897 * 1e6 (mol/mol -> part per million) = 8.047e-6
conv_rho= E*dtstep*8.047E-6/(rho_phy(I,k,J)*dz8w(i,k,j))
Both rho_phy(I,k,J) and dz8w(i,k,j) are WRF variables responding to the change in the pressure and temperature so the plume expansion is taken care of automatically.
So, the code should be
! on the fire mesh
!
! emission (g/m^2) = initial fuel load (kg/m^2) * fraction burned (1) * emission of the chemical species from the given fuel (g/kg)
emis_fgrid(i,j,ispecies) = fgip(i,j) * fuel_frac_burnt(i,j) * emis_fuel(ifuel(i,j),ispecies)
!
! average to the atmospheric mesh to get emis_grid(i,j,ispecies) (g/m^2)
!
! on the atmospheric mesh
!
! mols of air in the 1st layer (mol/m^2) = (air density (kg/m^3) * layer height (m)) / * molecular mass of air (kg/mol)
air_mols = (rho_phy(i,kts,j)*dz8w(i,kts,j) / 28.97e-3
!
! emissions (mols/m^2) = emissions (g/m^2) / molecular mass of the species (g/mol)
emis_mols = grid_emission(i,j,ispecies) / mols(ispecies) ! the constants mols(p_species) are probably in chem somewhere??
!
! add the concentration in ppmv to chem
chem(i,kts,j,p_species) = chem(i,kts,j,p_species) + 1e-6 * emis_mols / air_mols