The Smkmerge program is a second option for applying control matrices. Smkmerge can apply both multiplicative control matrices and reactivity control matrices; it is the only program that can do the latter. Because the overall purpose of Smkmerge is to create the model-ready input files for an AQM (as discussed in Section 2.18, “Creating model-ready emissions”, the result of using Smkmerge to apply control matrices is a controlled, model-ready file, as opposed to the controlled intermediate inventory file output by Grwinven.

Smkmerge is limited to applying one control matrix and one reactivity matrix for each SMOKE source category (area, mobile, or point). Therefore, if multiple reactivity control matrices need to be applied to create a single set of model-ready emission inputs, then the processing must be done as multiple SMOKE runs. This includes separating the sources that need different controls into separate inventory files and performing all SMOKE processing steps separately on the runs, using different reactivity controls for each. The resulting two or more sets of model-ready emissions should not have duplicate sources if the inventories were separated correctly at the start, and the model-ready files are combined using the Mrggrid program, as discussed in Section 2.18, “Creating model-ready emissions”.