4.4.24. Output source apportionment data

Source apportionment in SMOKE consists of grouping sources by characteristics (i.e. FIPS code, SCC, and point source information) and then tagging the emissions from those groupings for further analysis in the air quality model. The SMOKE programs Movesmrg and Smkmerge can optionally output the emissions in special files used for later source apportionment processing.

The following steps outline the process for creating the source apportionment output files:

  1. Define source groups using the SMKMERGE_GROUPS file

    The format for the SMKMERGE_GROUPS file is described in Section 8.10.11, “SMKMERGE_GROUPS: Source apportionment groups”. When assigning sources to groups, SMOKE will match each source to the most specific line in the SMKMERGE_GROUPS file. The hierarchy of assignment priority is listed below.

    1. Country/state/county code, SCC, plant ID, point ID [point sources only]

    2. Country/state/county code, SCC, plant ID [point sources only]

    3. Country/state/county code, plant ID, point ID [point sources only]

    4. Country/state/county code, plant ID [point sources only]

    5. Country/state/county code, SCC [non-biogenic sources only]

    6. Country/state code, SCC [non-biogenic sources only]

    7. SCC [non-biogenic sources only]

    8. Country/state/county code

    9. Country/state code

    10. Default group (country/state/county code = 0, SCC = 0)

  2. Define locations for the output files STACK_GROUPS_OUT (source group information), SGINLNTS_L (emissions data), and SRCGRP_REPORT (source group report file)

  3. For point source processing, use in-line plume rise calculation

    Review Section 4.4.19, “In-line Plume Rise Calculation in CMAQ model (as of version 4.7)” for instructions on configuring Elevpoint and Laypoint for in-line emissions processing.

  4. After completing other SMOKE processing, run Movesmrg (on-road mobile emissions using MOVES lookup tables) or Smkmerge with SMK_SRCGROUP_OUTPUT_YN set to Y

    When processing emissions using source apportionment, you can only run Smkmerge for a single source category (i.e. A, B, M, or P). For point source processing, Smkmerge cannot merge layers (MRG_LAYERS_YN must be N) and in-line emissions must be output (SMK_ELEV_METHOD must be 2). Movesmrg and Smkmerge will create both the source apportionment data files and the model-ready output files in a single run. For biogenics, if you are running Smkmerge for reporting purposes (i.e. to create state and county totals), make sure to set the units correctly for the source apportionment output data, typically the same as the model-ready output units.

  5. Review source grouping assignments

    After running Movesmrg or Smkmerge, the SRCGRP_REPORT file will list each source in the inventory and the group it was assigned to. You can review this report to verify that the sources were grouped as desired.