# Presentation: 735844

## Piedmont National Wildlife Refuge

- 16 February 2006
- Smoke Simulation Analysis
- Gary L. Achtemeier
- USDA Forest Service
- Athens, GA

## Task Description

- The following set of slides summarize a PB-Piedmont post-burn analysis of smoke movement in the aftermath of two (547 and 513 acre) prescribed burns conducted by the Piedmont National Wildlife Refuge. These burns were conducted on 16 February 2006. The model simulations run from 1600 EST 16 February through 0700 EST 17 February. Model smoke locations are compared with field observations collected by personnel from the Piedmont National Wildlife Refuge.

## Weather

- Weather during the burn and the post-burn smoke movement period was clear. A cold front approached Georgia from the northwest by the end of the simulation period. Winds gradually shifted from the southeast to the south. The below figure gives a measure of the strength of the large scale forcing during the analysis period. Forcing of 12.0 m/sec declined to 7.0 m/sec was sufficient to block drainage flow formation in northwest-southeast oriented valleys but to allow drainage flows in east-west oriented valleys. Forcing increased to 16.1 m/sec after 0300 17 February as the cold front approach and was sufficient to ventilate all but the deepest east-west oriented valleys. Strong ventilation may be the reason little smoke was observed on the morning of 17 February.

## Modeling Information

- PB-Piedmont Version 5.0-2006
- Grid spacing = 60m
- Domain size = 292x503 -> 17.5x30.2 km
- Visual domain = 13.7x16.4 km
- Weather data: Hourly METAR
- Elevation data: USGS 30 m DEM
- Elevation contour interval = 11 meters
- Elevation range is 88 – 218 meters

## The PB-Piedmont domain, roads, observation points for 16 February 2006. The yellow polygons enclose the burn sites. 

- The PB-Piedmont domain, roads, observation points for 16 February 2006. The yellow polygons enclose the burn sites.

## The modeled location of smoke on the ground assumes smoldering is coming from random locations within the model burn areas. Initial winds are from the south at 5.4 m/sec beginning at 1630 EST. Note that this image is just the viewing domain. The time is 1800 EST, 15 minutes before sunset.

## The smoke plume at 2000 16 February 2006. The plumes have broken into patches of smoke that are concentrated in the valleys located downwind from the burn sites. 

- The smoke plume at 2000 16 February 2006. The plumes have broken into patches of smoke that are concentrated in the valleys located downwind from the burn sites.

## The PB-Piedmont smoke plume at 0000 EST 17 February 2006. Smoke from the southern burn site has drained into and turned northwestward in the Okmulgee River valley (dark green strip oriented NW-SE). Smoke from the southern burn site has also been carried northwest to merge with smoke from the northern burn site. Red dots identify areas where smoke and fog may coexist.

## The PB-Piedmont smoke plume at 0600 LST 17 February 2006. Increased synoptic forcing has ventilated the valley west of the southern burn site and smoke is clearing out of the Okmulgee River Valley. Smoke is also being ventilated out of the valley between Points 19 and 21 west of the northern burn site. 

- The PB-Piedmont smoke plume at 0600 LST 17 February 2006. Increased synoptic forcing has ventilated the valley west of the southern burn site and smoke is clearing out of the Okmulgee River Valley. Smoke is also being ventilated out of the valley between Points 19 and 21 west of the northern burn site.

## Smoke Location Evaluation:Interpreting the Observations Shown in the Next Slide

- Red symbol means smoke observed
- Green symbol means smoke not observed
- Circle means model matched observation
- Triangle means model unsuccessful

## PB-Piedmont analysis & observations 0700 EST

- 5: No smoke (0625)

- 6: No smoke (0628)

- 7: No smoke (0632)

- 8: Smoke on unit (0634)

- 4: No smoke (0600)

- 9: Slight smoke (0636)

- 10: Slight smoke (0640)

- Click left mouse button to view observation points.

- 11: Slight smoke (0646)

- 12: No smoke (0649)

- 13: Slight smoke (0650)

- 14: Smoke (0654)

- 16: Slight smoke (0700)

- 17: No smoke (0607)

- 15: Slight smoke (0657)

- 18: No smoke (0609)

- 19: Slight smoke (0611)

- 20: Slight smoke (0616)

- 21: Slight smoke (0621)

## PB-Piedmont analysis & observations 0700 EST

- 23: No smoke (0635)

- 24: Thick smoke (0644)

- 25: Slight smoke (0648)

- 26: Thick smoke (0652)

- 22: No smoke (0630)

- 27: Thick smoke (0654)

- 28: Smoke (0701)

- Click left mouse button to view observation points.

- 29: Smoke (0706)

- 30: Slight smoke (0709)

- 31: Smoke (0711)

- 32: Smoke (0713)

- 34: Light smoke (0725)

- 35: Slight smoke (0731)

- 33: Slight smoke (0723)

## Summary:

- PB-Piedmont was correct at 22 of the 32 smoke/no-smoke observation points.
- Point 19 was recorded as a correct match because of the presence of smoke there at 0600. Observation was taken at 0611.
- PB-Piedmont failed to find smoke at Points 27-30. Smoke was never placed at these sites during the simulation. Synoptic forcing would have blown smoke away from these areas. The area was high ground and drainages would have sloped away from these points. Thus both synoptic forcing and drainage forcing would have combined to move smoke away from Points 27-30.
- One explanation for the failure to find smoke at Points 27-30 is that the smoke observed was from another burn site located on private land southeast from the northern burn site. A lot of burning was done during February 2006. PNWR smoke observers noted on their smoke reports that some smoke observed may have been coming from sites where burning was done several days earlier.

## Smoke Matrix

- Smoke Prediction

- Yes                 No

- Smoke Observation

-   No                Yes

- 16

- 6

- 1

- 9