Processing categories: area, mobile, point

The Temporal program produces a file with hourly inventory pollutant emissions. Unlike the SMOKE matrices produced by Cntlmat, Grdmat, and Spcmat, the output file from Temporal contains the actual emissions data. For all source categories, it uses temporal profiles, temporal cross-references, and the time zone of each source to create the hourly emissions output file. It can also read in day-specific and hour-specific inventory data in SMOKE format, and it uses the most detailed data it can when multiple types of data are available for the same source. For example, if a source had annual, day-specific, and hour-specific data, Temporal would use the hour-specific emissions. The program can also apply source-specific hourly profiles from the hour-specific data file, and it can override all temporal profiles and use temporally uniform profiles for all sources.

Temporal treats the temporal profiles as local profiles. In other words, the profile applied to the source is adjusted based on the difference between the time zone of the source (determined by the COSTCY file) and the output time zone (determined by the OUTZONE environment variable). SMOKE automatically considers Daylight Saving time when converting from a region’s standard time zone to the output time zone, and SMOKE can exclude regions that never use Daylight Saving time based on the COSTCY file. Note that Temporal has been tested for time zones in the Western Hemisphere, but we have not tested it for time zones in the Eastern Hemisphere.

Within the Temporal program, the processing occurs as follows:

Hourly temporal profiles can be applied for weekdays and weekend days by default in the system. By breaking up the processing into different periods, you can apply different temporal profiles for different days of the week. A future version of SMOKE will permit different hourly profiles for every day of the week in a single run of the Temporal program.

A special holidays file should be provided so that holidays can receive special treatment. This file specifies which daily profiles should be applied to holidays.

A many-step hierarchy is used in applying the temporal cross-referencing. SMOKE preferentially matches each source to the most specific line in the cross-reference file. When there are missing entries in the cross-reference file, Temporal first looks for cross-reference entries for other species at the same level in the search hierarchy before descending to the next level in the hierarchy. For example, if a source has a temporal cross-reference entry for CO but not for NO_x, Temporal uses the source-specific CO temporal cross reference entry for allocating NO_x from that source in preference to using a default NO_x temporal profile.

For area sources, the available combinations are the following, starting with the most specific. “7-digit SCC” means a 10-digit SCC with the last three digits set to zero. The maximum field width in SMOKE and its input files for SCC is 20 characters as of SMOKE v4.0. The 8 or 10 digit SCC are still supported, but if the SCC is greater than 10 digits the SCC hierarchial approach will not be supported. The SIC may also be up to 20 characters in length, but if the SIC is larger than 4 characters then the hierarchial approach will not be used. (NOTE: only for SCC less than or equal to 10 characters and SIC less than or equal to 4 characters)

For point sources, the available combinations depend on the source definition. A header is used in the file to indicate the source definition. For inventories, a source is defined as the unique combination of country/state/county code, plant ID, point ID, stack ID, segment, and SCC. “5-digit SCC” means a 10-digit SCC with the last 5 digits set to zero. If only 8-digit SCCs are available, these can be used and SMOKE will assume leading zeros. In this case, the “5-digit SCC” becomes a “3-digit SCC”. The maximum field width in SMOKE and its input files for SCC is 20 characters as of SMOKE v4.0. The 8 or 10 digit SCC are still supported, but if the SCC is greater than 10 digits the SCC hierarchial approach will not be supported. The SIC may also be up to 20 characters in length, but if the SIC is larger than 4 characters then the hierarchial approach will not be used.

The hierarchy of cross-referencing is the following. (NOTE: only for SCC less than or equal to 10 characters, SIC less than or equal to 4 characters)