6.17. Temporal

6.17.1. Description
6.17.2. Processing Order
6.17.3. Files and Environment Variables

6.17.1. Description

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. For mobile sources, Temporal also reads the emission factors created by Emisfac.

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:

  • Temporal profiles are assigned for all sources.

  • Monthly and day-of-week temporal profiles are applied.

  • Day-specific emissions or activities are read in and used to overwrite daily emissions for the appropriate sources

  • Hourly temporal profiles are applied.

  • Hour-specific emissions or activities are read in and used to overwrite hourly emissions for the appropriate sources.

  • Emission factors are applied to the hourly activity data (if any)

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 NOx, Temporal uses the source-specific CO temporal cross reference entry for allocating NOx from that source in preference to using a default NOx 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.

  1. Country/state/county code, 10-digit SCC, and pollutant

  2. Country/state/county code, 7-digit SCC, and pollutant

  3. Country/state code, 10-digit SCC, and pollutant

  4. Country/state code, 7-digit SCC, and pollutant

  5. 10-digit SCC and pollutant

  6. 7-digit SCC and pollutant

  7. Country/state/county code and 10-digit SCC

  8. Country/state/county code and 7-digit SCC

  9. Country/state code and 10-digit SCC

  10. Country/state code and 7-digit SCC

  11. 10-digit SCC

  12. 7-digit SCC

  13. Country/state/county code

  14. Country/state code

  15. Ultimate default (no pollutant, country/state/county code = 0, SCC = 0)

For mobile sources, the available combinations are given below. To specify an entry that is to match by vehicle type, the road class part of the SCC must be filled with zeros. If any warnings or errors are written during the read of the mobile temporal cross-reference file, the messages will use the mobile internal SCCs.

  1. Country/state/county code, road class, link ID, vehicle type, and process/pollutant

  2. Country/state/county code, road class, link ID, and process/pollutant

  3. Country/state/county code, road class, link ID, and vehicle type

  4. Country/state/county code, road class, and link ID

  5. Country/state/county code, road class, vehicle type, and process/pollutant

  6. Country/state/county code, road class, and process/pollutant

  7. Country/state/county code, vehicle type, and process/pollutant

  8. Country/state code, road class, vehicle type, and process/pollutant

  9. Country/state code, road class, and process/pollutant

  10. Country/state code, vehicle type, and process/pollutant

  11. Road class, vehicle type, and process/pollutant

  12. Road class and process/pollutant

  13. Vehicle type and process/pollutant

  14. Country/state/county code, road class, vehicle type

  15. Country/state/county code, road class

  16. Country/state/county code, vehicle type

  17. Country/state code, road class, vehicle type

  18. Country/state code, road class

  19. Country/state code, vehicle type

  20. Road class, vehicle type

  21. Road class

  22. Vehicle type

  23. Country/state/county code

  24. Country/state code

  25. Ultimate default (all values = 0)

For point sources, the available combinations depend on the source definition. A header is used in the file to indicate the source definition. (The header is required for IDA inventories). For IDA-formatted inventories, a source is defined as the unique combination of country/state/county code, plant ID, point ID, stack ID, segment, and SCC. This documentation applies to IDA-formatted inventories only. “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 hierarchy of cross-referencing is the following.

  1. Country/state/county code, 10-digit SCC, plant ID, point ID, stack ID, segment, and pollutant

  2. Country/state/county code, 10-digit SCC, plant ID, point ID, stack ID, and pollutant

  3. Country/state/county code, 10-digit SCC, plant ID, point ID, and pollutant

  4. Country/state/county code, 10-digit SCC, plant ID, and pollutant

  5. Country/state/county code, 10-digit SCC, plant ID, point ID, stack ID, and segment

  6. Country/state/county code, 10-digit SCC, plant ID, point ID, and stack ID

  7. Country/state/county code, 10-digit SCC, plant ID, and point ID

  8. Country/state/county code, 10-digit SCC, and plant ID

  9. Country/state/county code, 10-digit SCC, and pollutant

  10. Country/state/county code, 5-digit SCC, and pollutant

  11. Country/state code, 10-digit SCC, and pollutant

  12. Country/state code, 5-digit SCC, and pollutant

  13. 10-digit SCC and pollutant

  14. 5-digit SCC and pollutant

  15. Country/state/county code and 10-digit SCC

  16. Country/state/county code and 5-digit SCC

  17. Country/state code and 10-digit SCC

  18. Country/state code and 5-digit SCC

  19. 10-digit SCC

  20. 5-digit SCC

  21. Country/state/county code

  22. Country/state code

  23. Ultimate default (all values = 0)