CARBON_APPORTIONMENT - 19 Sep 2005 CMAQv4.5 includes an optional diagnostic model configuration that provides detailed information on the source origin of primary carbonaceous aerosol. This model version, referred to as the CMAQ Carbon Apportionment Model, tracks the contributions of elemental carbon and primary organic carbon from 10 different source categories or source regions. A pre-release version of this model has been described and evaluated by Bhave et al. (2004). In order to build the carbon apportionment version of the CTM executable program, several different modules, a different chemical mechanism, and a different IOAPI library must be specified in the model build script. You can modify the bldit.cctm.pgf script as follows and build the carbon apportionment version of the CCTM: 40c40 < set APPL = e2a --- > set APPL = ce2a 91c91 < set ModVdiff = ( module eddy $Revision; ) --- > set ModVdiff = ( module eddy_carb $Revision; ) 106,107c106,107 < #set ModAero = ( module aero3 $Revision; ) < set ModAero = ( module aero4 $Revision; ) --- > #set ModAero = ( module aero3_carb $Revision; ) > set ModAero = ( module aero4_carb $Revision; ) 110c110 < set ModAdepv = ( module aero_depv2 $Revision; ) --- > set ModAdepv = ( module aero_depv2_carb $Revision; ) 124c124 < set Mechanism = cb4_ae4_aq --- > set Mechanism = cb4_ae4ca_aq 160c160 < set ICL_IOAPI = ${M3LIB}/ioapi_3/fixed_src --- > set ICL_IOAPI = ${M3LIB}/ioapi_3/largeMXVARS3/fixed_src 199c199 < set LIB5 = "-L${IOAPI}" --- > set LIB5 = "-L${M3LIB}/ioapi_3/largeMXVARS3/${BLD_OS}2_x86pg -lioapi" Note: the number of species in the carbon apportionment model version exceeds the default upper limit in IOAPI (MXVARS3 = 120). To exceed this limit, the IOAPI library must be recompiled with the following changes: 1. In parms3.h, change MXVARS3 from 120 to a larger number (e.g., 540). 2. In PARMS3.EXT, change MXVARS3 to the value selected above. 3. In fixed_src/PARMS3.EXT, change MXVARS3 again. In the build script changes listed above, replace both occurrences of "largeMXVARS3" with the path to the new IOAPI library that you just created. Next, modify the run script as follows: 19,20c19,20 < set APPL = e2a < set CFG = e2a --- > set APPL = ce2a > set CFG = ce2a 102,103c102,103 < set EMISpath = $M3DATA/emis/tut02 < set EMISfile = e_32km_cb4.19990702.ncf --- > set EMISpath = $M3DATA/emis/tutcarb > set EMISfile = e_32km_cb4ae3ca.19990702.ncf Note: You can change the default scripts by using the Unix "patch" utility. Cut the indented section listed above into a file, say "mod." Then type, for example, "patch run.cctm mod." The carbon apportionment model will work with the same IC and BC files available for use with the standard CMAQ model. However, special processing is required to generate the emission input files. In addition to the standard list of emitted species, the model-ready emission files must contain the following variables: POA1, POA2, ... , POA9, PEC1, PEC2, ... , and PEC9. Note that these variables do not replace POA and PEC; they are additional variables. In the model, POA1 through POA9 represent primary organic aerosol from nine distinct source categories (or source regions) that the user wishes to track. POA represents primary organic aerosol from other miscellaneous source categories (or source regions). To yield results that are consistent with a standard CMAQ run, the sum of POA1 + POA2 + ... + POA9 + POA should be equal to POA in a standard CMAQ emission file. Similar statements apply for PEC1, PEC2, ..., PEC9, and PEC, which represent elemental carbon emissions. To track primary carbonaceous aerosol concentrations from different source categories, users may modify the GSPRO and GSREF files and rerun SMOKE in a manner similar to that described by Bhave et al. (2005). To track primary carbonaceous aerosol concentrations from different source regions, users must create their own emission processing procedure. In the run script created above, replace the EMISpath and EMISfile definitions to point to the newly-generated emission file. The carbon apportionment model may be operated with any combination of CB4 and SAPRC99 chemical mechanisms, and AERO3 and AERO4 aerosol modules. However, only the combination of CB4 & SAPRC99 was tested prior to the release of CMAQv4.5. Reference: Bhave, P.V., G.A. Pouliot, and M. Zheng, 2004, Source apportionment of primary carbonaceous aerosol using the Community Multiscale Air Quality model. Preprints, 27th NATO/CCMS International Technical Meeting on Air Pollution Modeling and its Applications, October 24-29, 2004, Banff, Alberta, Canada. NATO/CCMS, 25-32.