GEOS-Chem to CMAQv5.0
GEOS-Chem to CMAQ
Original authors: Havala Pye and Sergey Napelenok, Atmospheric Modeling and Analysis Division, US EPA
The objective of this information is to facilitate use of CMAQ. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. No endorsement should be inferred.
To map GEOS-Chem v9-01-01 to CMAQ v5.0 with CB05 and AERO6, two streams of output can be generated and mapped to CMAQ species. This includes the standard tracer output (ctm.bpch) and the non-standard CSPEC species output. Aerosol mappings assume GEOS-Chem species have been converted to micrograms per meter-cubed. Version 1.2 of the mapping is described below.
GEOS-Chem Tracers
The following CMAQ species can be mapped to GEOS-Chem tracers. Note that aerosol species from GEOS-Chem are assumed to be ug/m3 and gas-phase species are in ppm or ppmC as indicated by the mole C/mole tracer in input.geos. Tracers expressed in ppmC are listed in the GEOS-Chem manual and the number of carbons in a CB05 species can be found in the CB05 documentation.
| CMAQ species | GEOS-Chem Tracer |
|---|---|
| O3 | Ox - NOx i.e. (O3 + NO2 + 2NO3) - (NO + NO2 + NO3 + HNO2) |
| N2O5 | N2O5 |
| HNO3 | HNO3 |
| PNA | HNO4 |
| H2O2 | H2O2 |
| NTR | R4N2 |
| FORM | CH2O |
| ALD2 | 1/2 * ALD2 |
| CO | CO |
| MEPX | MP |
| PAN | PAN |
| PANX | PPN + PMN |
| OLE | 0.5 * 1/2 * PRPE |
| IOLE | 0.5 * 1/4 * PRPE |
| TOL | 1/7 * TOLU |
| XYL | 1/8 * XYLE |
| ISPD | MACR + MVK |
| SO2 | SO2 |
| ETHA | 1/2 * C2H6 |
| ASO4K | 0.0776 * SALC + 0.02655 * ( DST2 + DST3 + DST4 ) + SO4s |
| ASO4J | 0.99 * SO4 + 0.0776 * SALA + 0.0225 * ( DST1 ) |
| ASO4I | 0.01 * SO4 |
| ANH4J | 0.99 * NH4 + 0.00005 * ( DST1 ) |
| ANH4I | 0.01 * NH4 |
| ANO3J | 0.99 * NIT + 0.00020 * ( DST1 ) |
| ANO3I | 0.01 * NIT |
| ACLK | 0.5538 * SALC + 0.01190 * ( DST2 + DST3 + DST4 ) |
| ACLJ | 0.5538 * SALA + 0.00945 * ( DST1 ) |
| ANAJ | 0.3086 * SALA + 0.03935 * ( DST1 ) |
| AMGJ | 0.0386 * SALA |
| AKJ | 0.0114 * SALA + 0.03770 * ( DST1 ) |
| ACAJ | 0.0118 * SALA + 0.07940 * ( DST1 ) |
| AFEJ | 0.03355 * ( DST1 ) |
| AALJ | 0.05695 * ( DST1 ) |
| ASIJ | 0.19435 * ( DST1 ) |
| ATIJ | 0.0028 * ( DST1 ) |
| AMNJ | 0.00115 * ( DST1 ) |
| AOTHRJ | 0.50219 * ( DST1 ) |
| APOCJ (formerly AORGPAJ) | 0.999 * ( OCPI+OCPO ) + 0.01075 * ( DST1 ) |
| APOCI (formerly AORGPAI) | 0.001 * ( OCPI+OCPO ) |
| AECJ | 0.999 * ( BCPI+BCPO ) |
| AECI | 0.001 * ( BCPI+PCPO ) |
| NH3 | NH3 |
| AXYL1J | 0.03 * SOA5 |
| AXYL2J | 0.01 * SOA5 |
| AXYL3J | 0.11 * SOA5 |
| ATOL1J | 0.04 * SOA5 |
| ATOL2J | 0.04 * SOA5 |
| ATOL3J | 0.29 * SOA5 |
| ABNZ1J | 0.12 * SOA5 |
| ABNZ2J | 0.04 * SOA5 |
| ABNZ3J | 0.32 * SOA5 |
| ATRP1J | 0.33 * ( SOA1 + SOA2 ) |
| ATRP2J | 0.67 * ( SOA1 + SOA2 ) |
| AISO1J | 0.75 * SOA4 |
| AISO2J | 0.25 * SOA4 |
| ASQTJ | SOA3 |
| SV_XYL1 | 0.19 * SOG5 |
| SV_XYL2 | 0.06 * SOG5 |
| SV_TOL1 | 0.23 * SOG5 |
| SV_TOL2 | 0.23 * SOG5 |
| SV_BNZ1 | 0.06 * SOG5 |
| SV_BNZ2 | 0.23 * SOG5 |
| SV_TRP1 | 0.33 * ( SOG1 + SOG2 ) |
| SV_TRP2 | 0.67 * ( SOG1 + SOG2 ) |
| SV_ISO1 | 0.75 * SOG4 |
| SV_ISO2 | 0.25 * SOG4 |
| SV_SQT | SOG3 |
| APNCOMI | 0.4 * 0.001 * ( OCPI+OCPO ) |
| APNCOMJ | 0.4 * 0.999 * ( OCPI+OCPO ) + 0.0043 * ( DST1 ) |
| ANO3K | NITs + 0.0016 * ( DST2 + DST3 + DST4 ) |
| ASEACATK | 0.3685 * SALC |
| NH3 | NH3 |
| BENZENE | 1/6 * BENZ |
| ISOP | 1/5 * ISOP |
| PAR | 1.5/3 * C3H8 + 4/4 * ALK4 + 3/3 * ACET + 4/4 * MEK + 1/6 * BENZ |
| ALDX | RCHO |
| ASOIL | 0.95995 * ( DST2 + DST3 + DST4 ) |
The following GEOS-Chem species are not mapped to CMAQ: DMS, MSA, ALPH, LIMO, ALCO
GEOS-Chem Species (tropospheric only)
The following CMAQ species can be mapped to GEOS-Chem species from the CSPEC array:
| CMAQ species | GEOS-Chem species |
|---|---|
| NO | NO |
| NO2 | NO2 |
| NO3 | NO3 |
| HONO | HNO2 |
| MGLY | MGLY |
Other information
- Default/clean boundaries were specified for the following species:
- GLY
- ETH
- AALKJ
- SV_ALK
- ACORS
- AISO3J
- SULF
- AOLGBJ
- AOLGAJ
- Particle number and surface area boundaries were adjusted to maintain consistent distributions. This is done automatically in the code that is planned for distribution with CMAQv5.0.
- SOA was speciated based on parent hydrocarbon identity and volatility of the mass contained within each species/tracer. Information about the contribution of various hydrocarbons to the lumped GEOS-Chem tracers was taken from Chung and Seinfeld 2002 and Liao et al. 2007 for biogenics and Henze et al. 2008 for aromatics, and coupled with outflow from the Eastern U.S. in a "typical" CMAQ continental U.S. simulation.
Chung, S. H., and Seinfeld, J. H.: Global distribution and climate forcing of carbonaceous aerosols. J. Geophys. Res., 107(D19), 4407, 2002.
Henze, D. K., Seinfeld, J. H., Ng, N. L., Kroll, J. H., Fu, T. M., Jacob, D. J. and Heald, C. L.: Global modeling of secondary organic aerosol formation from aromatic hydrocarbons: high- vs low-yield pathways. Atmos. Chem. Phys., 8(9), 2405-2420, 2008.
Liao, H., Henze, D. K., Seinfeld, J. H., Wu, S. L. and Mickley, L. J.: Biogenic secondary organic aerosol over the United States: Comparison of climatological simulations with observations. Journal of Geophysical Research-Atmospheres, 112(D6), 2007.