Finally, the Temporal program must output intermediate files. The hourly emissions are written to the ATMP, MTMP, and PTMP I/O API files. Unlike the other major SMOKE intermediate files (e.g., the matrices), the actual emissions (not just factors) are written to this file. This is because day-specific and hour-specific emissions can be impossible to convert into factors since the annual inventory emissions for the day- or hour-specific sources could be zero and factors would not be able to change that.

If Temporal has more than 120 variables to output (the limit for the number of variables in an I/O API file), Temporal opens as many files (using the FileSetAPI wrapper) as are needed to store the data. SMOKE also estimates how large the output files will be using 120 variables per file and automatically lowers the number of variables that will be put in each I/O API output file to ensure that the files use less than 2 GB of disk space. In addition, Temporal writes the supplementary files ATSUP, MTSUP, or PTSUP, which contain the temporal profiles assigned to each source. The structures of the SMOKE intermediate files output by Temporal are provided in Section 9.15, “Temporal”.