4.4.17. Plume Rise Calculation for Fires

Starting with version 2.2, SMOKE contains an approach for computing plume rise for wildfire/prescribed fires using the Bluesky Pouliot-Godowitch plume rise algorithm (http://www.epa.gov/ttn/chief/conference/ei14/session12/pouliot.pdf). In SMOKE version 2.2, SMOKE can compute hourly plume rise from precomputed hourly heat flux, fuel loading and area burned data using the Bluesky CONSUME model. The SMOKE preprocessor Bluesky2Inv that converts the output from the CONSUME model into SMOKE-readable annual and daily inventory files (Section 5.3.3, “BlueSky2Inv).

Starting with SMOKE version 2.3, SMOKE can compute hourly plume rise from an intenally computed heat flux using area burned and fuel loading data. This approach allows SMOKE to compute hourly heat flux based upon daily area burned, fuel loading, material burned and a constant default heat content (8000 BTU/lb) (Equation 1). The daily heat flux and emissions are temporally allocated to hourly values based upon the duration of the fire (begining and ending hours). However, if there is a precomputed heat flux available as a daily inventory, Smkinven will not internally compute the heat flux and drop the begin and end hours of fire.

  1. Heat Flux (BTU/hr) = [ Area Burned (acre/day) x Fuel Loading (tons/acre) x Heat Content (BTU/lb) x (2000lb/ton) ] / Duration of fire (hr/day)

Detail information on how the fire emissions are calculated can be found on the proceeding presented by Pouliot et al., (2005).

The SMOKE plume rise requires two ORL formatted files for wildfire/prescribed fires. The master #ORL FIRE file (Section, “ORL FIRE Format”) contains the fire characteristics including country/state/county code, fire idenfication code, geographic coordinate, fire name, heat content, material burned and NFDRS code. The day-specific #ORL FIREEMIS file (“Section, “ORL FIREEMIS Emission Format””) includes daily pollutant emissions, area burned, fuel loading, optional heat flux, and fire begining and ending time. Starting with SMOKE version 3.7, Smkinven can process these master and daily fire inventories with precomputed heat flux using current point FF10 formats, #FF10_POINT file (“Section, “FF10 Format””) and #FF10_DAILY_FF10 file (“Section, “ FF10 Format””)

Regardless whether the heat flux for wildfires is precomputed or internally computed, the fire-specific plume rise algorithm converts the heat flux to a bouyancy flux for use in the plume rise calculation. See more detail at Section, “Plume rise calculation for fires”

NOTE: SMOKE requires that the fire inventory pollutant names are copied to the Chemical Abstracts Service (CAS) number column in the inventory table (INVTABLE) file (See Section 8.10.4, “INVTABLE: Inventory table”).

  1. To compute plume rise for fires using SMOKE, following these steps. Add the fire inventory variables to the INVTABLE file:

    HFLUX           HFLUX                    Y     1 N N N N   0 tons/yr
    HEATCONTENT     HEATCONTENT              Y     1 N N N N   0 tons/yr
    FUEL_LOAD       FUEL_LOAD                Y     1 N N N N   0 tons/yr
    ACRESBURNED     ACRESBURNED              Y     1 N N N N   0 tons/yr
    BEGHOUR         BEGHOUR                  Y     1 N N N N   0 tons/yr
    ENDHOUR         ENDHOUR                  Y     1 N N N N   0 tons/yr
  2. Run Smkinven with these settings,

    • Set RUN_SMKINVEN to Y


    • Set CHECK_STACKS_YN to N

  3. Do not run Elevpoint,

    • Set RUN_ELEVPOINT to N

    • Set SMK_ELEV_METHOD to 0

    • Set SMK_PING_METHOD to 0

  4. Run Laypoint with these settings,

    • Set RUN_LAYPOINT to Y

    • Set FIRE_PLUME_YN to Y

    • Set HOURLY_FIRE_YN to Y

    • Set SMK_SPECELEV_YN to N

  5. Run Smkmerge with theses settings,

    • Set RUN_SMKMERGE to Y


  6. Set these multiple program control settings.

    • Set DAY_SPECIFIC_YN to Y


    • Set SMK_PING_METHOD to 0

    • Set QA_TYPE to part2