The Temporal program uses a cross-reference file and a temporal profiles file to assign the temporal profiles to the inventory sources. The cross-reference file can assign the profiles using a hierarchy that is based on the source characteristics. A detailed list of valid assignments is given in Section 4.17, “Temporal” with the detailed description of the Temporal program. The cross-reference assigns a monthly, weekly, and diurnal profile to each source, and can also assign default profiles to sources that don’t have more specific matches in the cross-reference file. When default assignments are made by the Temporal program, you can optionally choose to have warnings given for all of these assignments, using the REPORT_DEFAULTS option.

The temporal profiles file has different sections that contain the monthly, weekly, and diurnal profiles. Additionally, you may provide different weekend (Saturday, Sunday) and weekday (Monday through Friday) diurnal profiles, or you may provide a different set of diurnal profiles for each day of the week.

When using multiple diurnal profiles, a given source must use a diurnal profile with the same profile code for each day. For example, if a source uses diurnal profile 1 for Monday, it will also use profile 1 for Tuesday, but Monday’s profile 1 can be different than Tuesday’s profile 1.

For weekly profiles, Temporal evaluates the TPFLAG setting (set by Smkinven as explained in Section 2.8.13, “Set the weekday averaging approach”) and uses the weekly-normalized weekly profiles or weekday-normalized weekly profiles, depending on the setting.

One limitation of using monthly, weekly, and diurnal profiles is that there is no week-to-week variation within a month. For example, all Tuesdays in a month use the same emissions profile (unless one happens to be a holiday, see Section 2.9.5, “Holiday processing”). This limitation can be overcome by using day-specific emissions data (only for point sources).