# Presentation: 944968

## South Carolina Forestry Commission

- February 9, 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 a 100 acre hazard reduction burn conducted by the South Carolina Forestry Commission. The burn was conducted on 9 February 2006. The model simulations run from 1600 EST 9 February through 0800 EST 10 February. The site was located on the coastal plain of South Carolina.

## Weather

- Weather during the burn and the post-burn smoke movement period was mostly clear. A weak high pressure system moved over South Carolina during the night, shifting the synoptic forcing to blow from the south. The geostrophic wind speed, a measure of the strength of the forcing by the large scale (synoptic) wind field ranged from 3.10 m/sec to 6.8 m/sec. This weak forcing was strong enough to oppose drainage wind formation in the coastal plain.

## Modeling Information

- PB-Piedmont Version 5.0-2006
- Grid spacing = 60 m
- Domain size = 321x335 -> 19.3x20.1 km
- Visual domain = 19.3x20.1
- Weather data: Hourly METAR
- Elevation data: USGS 30 m DEM
- Elevation contour interval = NA
- Elevation range is NA

## The full 19.3x20.1 km model domain captures the drainages surrounding the burnsite (white square).

## The PB-Piedmont viewing domain and observation points (6,7,8) for 9 February 2006 where dense smoke was observed most of the night. The yellow polygon encloses the 1000 acre burn site. 

- The PB-Piedmont viewing domain and observation points (6,7,8) for 9 February 2006 where dense smoke was observed most of the night. The yellow polygon encloses the 1000 acre burn site.

## The plume at 1700 EST, 9 February 2006 blows from the north away from the observation sites. 

- The plume at 1700 EST, 9 February 2006 blows from the north away from the observation sites.

## 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 2200 EST, 9 February 2006. Red areas indicate where smoke and fog may coexist.

- 6: Thick smoke (2230)

- 7: Thick smoke (2230)

- 8: Thick smoke (2230)

- Click left mouse button to view observation points.

## Summary:

- PB-Piedmont correctly placed smoke or no smoke at 3 of the 3 observation sites.
- Very weak synoptic forcing changed the winds from blowing from the south to blowing to the north. The outcome on the existing smoke plume was to scatter smoke widely over the domain.

## 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 2200 EST, 9 February 2006. Red areas indicate where smoke and fog may coexist.

- 6: Thick smoke (2230)

- 7: Thick smoke (2230)

- 8: Thick smoke (2230)

- Click left mouse button to view observation points.

## Summary:

- PB-Piedmont correctly placed smoke or no smoke at 3 of the 3 observation sites.

## 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 2200 EST, 9 February 2006. Red areas indicate where smoke and fog may coexist.

- 6: Thick smoke (2230)

- 7: Thick smoke (2230)

- 8: Thick smoke (2230)

- Click left mouse button to view observation points.

## Summary:

- PB-Piedmont correctly placed smoke or no smoke at 2 of the 3 observation sites.
- Synoptic flow dominated drainage flows to divert smoke to blow to the northwest.
- Investigation of surrounding airport winds showed winds blowing from the south to southwest, still not sufficient to place smoke over the observed sites.
- The best explanation for the smoke at observations 6 and 7 is smoke blown north from another burn site located south of the area.

## Summary:

- PB-Piedmont correctly placed smoke or no smoke at 2 of the 3 observation sites.

## Overall Summary:

- PB-Piedmont correctly placed smoke or no smoke at 8 of the 9 observation sites.
- From the description given by the observer, it is not clear whether smoke was observed at all three sites at 0800. He reported only that the area was still in heavy smoke.

## Smoke Matrix

- Smoke Prediction

- Yes                 No

- Smoke Observation

-   No                Yes

- 8

- 0

- 0

- 1