5.3.7. Geofac Description Processing Order Files and Environment Variables Description

The Geofac program provides a means for adjusting emissions by grid cell after SMOKE has already created model-ready inputs. For example, the program could be used to zero emissions from all grid cells that intersect a certain state, which would be a rough approximation of removing that state’s inventory from the model-ready files. Although it is more accurate to modify the emissions using the Cntlmat program, that approach takes longer and is possible only if the SMOKE input files used to create the model ready emissions are still available. Geofac is useful in situations where speed and simplicity are more important than the accuracy of the emissions, or when only the gridded model-ready inputs are available and the inventories used to create them are not.

Geofac reads in a gridded 2-D or 3-D SMOKE emissions file (output from the Smkmerge program) and multiplies the emissions with a user-supplied adjustment factor for each individual species in the emissions file. The factors are assigned by grid-cell regions, which are defined by the input “mask” file. Each grid cell either receives the factors or it does not (the mask is simply an on-off switch). The resulting hourly, gridded, speciated emissions data are output to a new I/O API file with the same spatial and temporal resolution and the same model species with different values. Processing Order

This optional program can be run after Smkmerge and before either Mrggrid (if it is being used to merge several Smkmerge output files together) or the AQM of interest. Files and Environment Variables Input Files
File Name Format Description
GEOMASK I/O API NetCDF Gridded, time-independent file that assigns a 1 to any grid cell whose emissions you want to adjust. The emissions from INFILE in grid cells that have a 1 in GEOMASK are multiplied by the factor provided in SPECFACS. All other emissions and grid cells are untouched.
INFILE I/O API NetCDF Hourly, gridded, speciated inputs from Smkmerge. INFILE should be set to logical file name AGTS_[L|S], BGTS_[L|S], MGTS_[L|S], PGTS_[L|S], PGTS3D_[L|S], EGTS_[L|S], or EGTS3D_[L|S], which are the output files from Smkmerge.

File that lists the species name and the factor to be applied to all grid cells with a 1 value in the GEOMASK file. The species name must be in columns 1-16 and the factor in columns 17-22. For example, the following SPECFACS file sample would multiply NO and NO2 emissions by 1.3 (30% increase) and multiply PAR by 0.6 (40% decrease).

NO              1.3
NO2             1.3
PAR             0.6 Input Environment Variables

None Output Files
File Name Format Description
LOGFILE ASCII Log generated from executing Geofac
OUTFILE I/O API NetCDF Hourly, gridded, speciated emissions, adjusted based on GEOMASK and SPECFACS.