Emission conversion from CB6AE7 to CB5AE5

SMOKE
1

Dear all,

I intend to downgrade my emission speciation from CB6AE7 to CB5AE5, and your help is greatly appreciated.

My emission species are as follows:

AACD
ACET
ACROLEIN
ALD2
ALDX
ALD2_PRIMARY
APIN
BENZ
BUTADIENE13
CH4
CH4_INV
CL2
CO
CO2_INV
ETH
ETHA
ETHY
ETOH
FACD
FORM
FORM_PRIMARY
HCL
HONO
IOLE
ISOP
IVOC
KET
MEOH
N2O_INV
NAPH
NH3
NH3_FERT
NO
NO2
NVOL
OLE
PAL
PAR
PCA
PCL
PEC
PFE
PH2O
PK
PMC
PMG
PMN
PMOTHR
PNA
PNCOM
PNH4
PNO3
POC
PRPA
PSI
PSO4
PTI
SO2
SOAALK
SULF
TERP
TOL
UNK
UNR
XYLMN

While the emission I need in CB5AE5 is as follows:

ALD2
ALDX
APIN
BPIN
BENZENE
CH4
CL2
CO
ETH
ETHA
ETOH
FORM
HCL
HONO
IOLE
ISOP
MEOH
NH3
NR
NO
NO2
NVOL
OLE
PAR
PEC
PMC
PMFINE
PNO3
POC
PSO4
SESQ
SO2
SULF
TERP
TOL
UNK
UNR
XYL

I have been searching through the forum, speciation tool manual, and TSDs. I understand that differences include 3 steps, downgrading from CB6 to CB5, and downgrading from AE7 to AE6, and from AE6 to AE5.

For conversion from CB6 to CB5, as mentioned in " UPDATES TO THE CARBON BOND MECHANISM FOR VERSION 6 (CB6)", I see the difference is new explicit species for PRPA, ETHY, ACET, KET, and new definition for BENZEN. For the first four I do not worry because I am downgrading, and for the BENZEN, I am recalculating BENZ as PAR + 5 NR ( NR comes from PRPA and PAR in CB6 emission).

For the conversion from AE7 to AE6, as mentioned in Does old emission input data work with new version of CMAQ-5.3.1? - #2 by Havala.Pye , I will use naphthalene to calculate XYL needed in CB5. But I do not know how to consider splitting APIN from TERP (do I need to sum these two?)

I also have BPIN in my CB5AE5 emission which I do not know where to get it from (I need to have SESQ as well).

Do I need to add ALD2_PRIMARY and ALD2 to have downgraded ALD2, (Likewise for FORM, and CH4 and CH4_INV)

And for downgrading from AE6 to AE5, I notice that I miss many species, while I have to calculate PMFINE.

And after all, is there a 1 to 1 relation between the rest of the species? Thank you very much.

@Ben_Murphy @bbaek @Havala.Pye @hogrefe.christian @eyth.alison will you please help me with the process?

Thanks again.

2

To go from CB6 with ae7 to CB6 with ae6, you should sum all monoterpenes together. Sesquiterpenes can be obtained from running BEIS in-line in CMAQ. You may need to check if your input (file) monoterpenes include biogenic emissions or just anthropogenic monoterpenes. If all your monoterpenes are in files (not created in CMAQ during runtime), you can do rough respeciation using literature ratios of a-pinene and/or b-pinene to all other monoterpenes and the DESID utility (GMD - The Detailed Emissions Scaling, Isolation, and Diagnostic (DESID) module in the Community Multiscale Air Quality (CMAQ) modeling system version 5.3.2).

3

Thank you very much @Havala.Pye. Is that all I should take care of? How about going from AE6 to AE5?
Can I also get some help with my rest of questions please?

4

Hello, To go from AE6 to AE5, you can use information on the CMAQv5.0 (ae6) vs 4.7.1 (ae5) implementation here: CMAQv5.0 PMother speciation - CMASWIKI. There may be additional gas-phase updates required (you may need to compare the mechanisms (GC*nml) then and now).