SULFATE_TRACKING - 15 Sep 2005 CMAQv4.5 includes an optional diagnostic model configuration that provides detailed information on the modeled sulfur budget. This model version, referred to as the CMAQ Sulfate Tracking Model, tracks sulfate production from the gas-phase and the five aqueous-phase chemical reactions, as well as contributions from direct emissions and initial and boundary conditions. Each of the tracked species is advected, diffused, processed through clouds, and deposited (both wet and dry) individually. The CMAQ sulfate tracking model is a valuable tool in examining the nonlinearities in the production of sulfate. NOTE: CURRENTLY, THE SULFATE TRACKING MODEL ONLY OPERATES WITH THE "aero3" (AE3) AND "cloud_radm" MODULES. WE PLAN TO EXTEND THE SULFATE TRACKING CAPABILITY TO INCLUDE THE "aero4" (AE4) AND "cloud_acm" MODULES IN THE NEXT RELEASE. In order to build the sulfate tracking version of the CTM executable program, several modules and a different chemical mechanism must be specified in the model build script. You can modify the bldit.cctm.linux script as follows and build the sulfate tracking version of the CCTM: 40c40 < set APPL = e2a --- > set APPL = se2a 91c91 < set ModVdiff = ( module eddy $Revision; ) --- > set ModVdiff = ( module eddy_sulf $Revision; ) 106,107c106,107 < #set ModAero = ( module aero3 $Revision; ) < set ModAero = ( module aero4 $Revision; ) --- > set ModAero = ( module aero3_sulf $Revision; ) > #set ModAero = ( module aero4 $Revision; ) 110c110 < set ModAdepv = ( module aero_depv2 $Revision; ) --- > set ModAdepv = ( module aero_depv2_sulf $Revision; ) 113,114c113,114 < #set ModCloud = ( module cloud_radm $Revision; ) < set ModCloud = ( module cloud_acm $Revision; ) --- > set ModCloud = ( module cloud_radm_sulf $Revision; ) > #set ModCloud = ( module cloud_acm $Revision; ) 124c124 < set Mechanism = cb4_ae4_aq --- > set Mechanism = cb4_ae3st_aq Then modify the run.cctm script as follows: 19,20c19,20 < set APPL = e2a < set CFG = e2a --- > set APPL = se2a > set CFG = se2a Note: You can change the default script by using the Unix "patch" utility. Cut the indented section listed above into a file, say "mod." Then type "patch run.cctm mod." The sulfate tracking model will work with the existing IC file, BC file, and emissions files available for use with the standard CMAQ model. No additional processing is required to prepare input data for this model version. The output concentration & deposition files will include additional species beyond the normal species list. These new output species are listed in Table 1 below. Table 1. Sulfate Tracking Species List ========================================================================= species name description ========================================================================= ASO4AQH2O2J ASO4J produced by aqueous-phase hydrogen peroxide oxidation reaction: H2O2 + S(IV) -> S(VI) + H2O ASO4AQO3J ASO4J produced by aqueous-phase ozone oxidation reaction: O3 + S(IV) -> S(VI) + O2 ASO4AQFEMNJ ASO4J produced by aqueous-phase oxygen catalyzed by Fe+++ and Mn++ oxidation reaction: O2 + S(IV) -> S(VI) ASO4AQMHPJ ASO4J produced by aqueous-phase methyl hydrogen peroxide oxidation reaction: MHP + S(IV) -> S(VI) ASO4AQPAAJ ASO4J produced by aqueous-phase peroxyacetic acid oxidation reaction: PAA + S(IV) -> S(VI) ASO4GASI ASO4I nucleated and/or condensed following gas-phase reaction: OH + SO2 -> SULF + HO2 ASO4GASJ ASO4J nucleated and/or condensed following gas-phase reaction: OH + SO2 -> SULF + HO2 ASO4EMISJ ASO4J from source emissions ASO4ICBCI ASO4I from boundary and initial conditions ASO4ICBCJ ASO4J from boundary and initial conditions SULF_ICBC Sulfuric acid vapor (SULF) from boundary and initial conditions =========================================================================