A common change to the SMOKE configuration is to select a speciation approach for an air quality model and chemical mechanism.
In Chapter 4, How to Use SMOKE, we noted that many speciation files are available for download from EPA. In this section, we describe how to use the SPC
value in the Assigns file to select these.
SMOKE provides several chemical mechanisms that one can select for modeling. In the default SMOKE configuration, only a few small changes are necessary to the Assigns file and script to use a different chemical mechanism.
Set the SPC
setting in the Assigns file.
The SPC
setting in the Assigns file controls which chemical mechanism is used by the scripts and SMOKE programs. Depending on what
source categories you are modeling, the air quality model that you are using, and the chemical mechanism for that air quality
model. See the default data files described in Chapter 4, How to Use SMOKE for the actual file names that will be used for each source category. Where different files are needed for different source
categories, the Assigns file will automatically detect this and set the GSPRO
and GSREF
files accordingly.
Determine whether VOC-to-TOG or ROG-to-TOG is needed and set script accordingly.
If your inventory contains the pollutant VOC or ROG and you are modeling for CMAQ, UAM, or CAMX, then you will need to use SMOKE’s GSCNV
file to convert the VOC or ROG mass to TOG mass.
The SMOKE Spcmat program will use the GSCNV
file if the POLLUTANT_CONVERSION
setting in the script is Y. This is the default configuration for the CMAQ run scripts.
If your inventory contains TOG, then the POLLUTANT_CONVERSION
setting in the run script should be set to N.
Ensure that the inventory pollutants that need speciation match the inventory pollutants in the speciation profiles and cross-reference files.
All of the pollutants in your inventory that you wish to include in the outputs must have valid profiles in the GSPRO
and GSREF
files. If the pollutant is left out of the GSREF
file, the pollutant will be dropped from modeling (in some cases, this is desirable, but a warning will be generated by Spcmat). For each pollutant in your inventory check that:
The pollutant has one or more entries in the GSREF
file. In some cases, you may have to add entries. For example, not all GSREF
files have “ROG” entries, but these can easily be added simply by copying the VOC assignments and changing the VOC label to ROG.
For CMAQ, UAM, and CAMX and the pollutant is VOC or ROG, check that the TOG profiles are in the GSPRO
file.
For all models and all other pollutants, check that the profiles are included in the GSPRO
file.
Ensure that the correct Assigns file is used in your run scripts.
Create and install the GSPRO
file.
If only a few changes will be made to a GSPRO
file, you can simply copy an existing GSPRO
file to a new file. If more extensive changes are needed to create a new mechanism, currently, there is no utility for creating
a GSPRO
file in SMOKE. For now, users must use the file format in Chapter 8, SMOKE Input Files and a high degree of expertise to develop new GSPRO
files.
Install the GSPRO
file in the
directory. For the default $GE_DAT
GSPRO
file for that chemical mechanism (i.e., the one that applies to the most source categories), name the file gspro.
. If your speciation profile is specific to a certain source category, name the $SPC
.txtGSPRO
file as follows:
area/non-road mobile: gspro.
$SPC
.a.txt
on-road mobile: gspro.
$SPC
.m.txt
point: gspro.
$SPC
.p.txt
Create and install the GSREF
file.
You may be able to simply copy a GSREF
file to a new name, depending on whether the profile codes are different for your new mechanism. In many cases, the same
profile codes are used (e.g., from the SPECIATE database), but the profiles themselves are all that have changed.
If you need to create a new GSREF
from scratch, you will need to ensure that all of the SCCs and all of the pollutants in the inventory have profile assignments.
Any pollutant in the inventory that is not included in the GSREF
file will be dropped from modeling. Any SCC that is not included will be assigned the default profile, which is the profile
assigned to SCC = 0.
Name the GSREF
file using a similar approach as for the GSPRO
file, but use the “gsref” prefix instead of the “gspro” prefix. Therefore, the default file for that chemical mechanism (the one that applies to the most source categories) should
be named gsref.
. Any source-category-specific files should use the names as follows:
$SPC
.txt
area/non-road mobile: gsref.
$SPC
.a.txt
on-road mobile: gsref.
$SPC
.m.txt
point: gsref.
$SPC
.p.txt
Create the pollutant-to-pollutant conversion file, if necessary.
If the speciation profiles change or new profiles are added for VOC speciation, a GSCNV
file must be created accordingly. This can be accomplished by copying and editing the example GSCNV
file or creating a new GSCNV
file from scratch. This requires a high degree of expertise and must be closely coordinated with creating the GSPRO
file.
Edit the INVTABLE
file.
Particularly for toxics modeling, changes to the GSPRO
file must be coordinated with changes to the INVTABLE
file in the following ways:
If the definition of NONHAPVOC changes, the INVTABLE
definition of NONHAPVOC must change as well.
If there are new explicit model species, these must be identified in the INVTABLE
file.
If there are new model species that are not part of the chemical mechanism, these must be identified in the INVTABLE
file.
If there are new pollutants, these must be included in the INVTABLE
file (as well as the raw inventories, of course).
Coordinate with MOVES inputs.
When processing using on-road mobile emissions and SMOKE running MOVES, users need to create the MEPROC
file that contains a list of MOVES pollutants by emissions processes created by MOVES. This SMOKE input need to be coordinated
so that the pollutants expected by the chemical mechanism are all created by SMOKE/MOVES. This requires that the MEPROC
file have all pollutant/process combinations for the required pollutants and that the MOVES inputs are configured to generate
emissions for those pollutants. The MEPROC
file is documented in Section 8.9.2.1.4, “MEPROC
: List of mobile emission processes and associated activities and pollutants”. The MOVES inputs are documented in the MOVES manual, and the limitations placed on these files by SMOKE are documented in
Section 4.4.12, “Use MOVES for on-road mobile sources”.
Edit the Assigns file and scripts
Make sure to change the SPC
variable in your Assigns file to the one for your new chemical mechanism. Also make sure that your run scripts use the Assigns
file with the correct SPC
setting.
Speciation assignments can be changed so that different speciation profiles are used for certain SCCs and pollutants or to
add SCCs and pollutants. You will need to ensure that all of the SCCs and all of the pollutants in the inventory have profile
assignments. Any pollutant in the inventory that is not included in the GSREF
file will be dropped from modeling. Any SCC that is not included will be assigned the default profile, which is the profile
assigned to SCC = 0.
Adding entries to an existing cross-reference file.
Edit an existing cross-reference file or copy it to a new file for editing. Insert the new speciation assignments based on the format of the file, described in Chapter 8, SMOKE Input Files.
Create new speciation cross-reference file(s) for your case.
Copy the speciation cross-reference (GSREF
) file for the chemical mechanism that you are using (or a chemical mechanism that is most similar to the one you have created).
Edit the speciation profile assignments using the file format, described in Chapter 8, SMOKE Input Files. The naming convention for the new file must be consistent with the convention described in the previous subsection.
Change the pollutant-to-pollutant conversion file.
If different SCCs get different profiles, then the GSCNV
file must be changed as well. The VOC-to-TOG factor in the GSCNV
depends on the profile that has been assigned to an SCC. So, the factor must be consistent with the profile assigned. Calculating
the VOC-to-TOG factor requires some expertise, and this is outside the scope of this manual. However, if you change an SCC
to use an existing profile, you can determine the correct VOC-to-TOG factor by first finding another SCC that uses that profile
and then setting the VOC-to-TOG factor to be the same as the one for that other SCC.
If any new files are created, ensure that the Assigns file uses all new files.
Make sure that the SPC
setting in the Assigns is correct and that the Assigns file will set the GSPRO
, GSREF
, and GSCNV
files so that any new files will be used by the programs.
The definition of NONHAPVOC and NONHAPTOG simply must be consistent between the GSPRO
file and the INVTABLE
file. This change applies only to chemical mechanisms that use VOC model species and can therefore benefit from the integration
of toxics and criteria VOC. This includes all models that SMOKE supports.
Edit the INVTABLE
file.
You can add pollutants and change their NONHAPVOC status using the INVTABLE
file format provided in Chapter 8, SMOKE Input Files.
Create new speciation profiles.
The speciation profiles must use the same definition of NONHAPVOC or NONHAPTOG. The header of the file must be updated to reflect the new definitions. The profiles for NONHAPVOC and NONHAPTOG must also be updated to be consistent. Finally, all other TOG profiles must be updated to be consistent with the definition.
Coordinate with MOVES inputs.
When processing using on-road mobile emissions and SMOKE running MOVES, users need to create the MEPROC
file that contains a list of MOVES pollutants by emissions processes created by MOVES. This SMOKE input need to be coordinated
so that the pollutants expected by the chemical mechanism are all created by SMOKE/MOVES. This requires that the MEPROC
file have all pollutant/process combinations for the required pollutants and that the MOVES inputs are configured to generate
emissions for those pollutants. The MEPROC
file is documented in Section 8.9.2.1.4, “MEPROC
: List of mobile emission processes and associated activities and pollutants”. The MOVES inputs are documented in the MOVES manual, and the limitations placed on these files by SMOKE are documented in
Section 4.4.12, “Use MOVES for on-road mobile sources”.