# Presentation: 937152

## South Carolina Forestry Commission

- March 8, 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 a 60 acre prescribed burn conducted by the South Carolina Forestry Commission. The burn was conducted on 8 March 2006. The model simulations run from 1600 EST 8 March through 0800 EST 9 March. This case was run with a 60 m grid.
- Field personnel operated throughout the night beginning at 2130 EST 8 March through 0600 EST 9 March to observe smoke.

## Weather

- Weather during the burn and the post-burn smoke movement period was mostly clear. A strong low pressure center over the mid-Mississippi valley combined with a high pressure center in the Atlantic Ocean off the coast of South Carolina to produce  moderately strong synoptic forcing over the burn site. This pattern persisted throughout the analysis period. The geostrophic wind speed, a measure of the strength of the forcing by the large scale (synoptic) wind field ranged between 11-17 m/sec. This forcing would oppose the formation of drainage flows in shallow valleys of the upper coastal plain.

## Modeling Information

- PB-Piedmont Version 5.0-2006
- Grid spacing = 60 m
- Domain size = 315x311 -> 18.9x18.7 km
- Visual domain = 5.1x4.9 km
- Weather data: Hourly METAR
- Elevation data: USGS 30 m DEM
- Elevation contour interval = 5 meters
- Elevation range is 129-199 meters

## The full 18.9x18.7 km model domain shows the location of the burn site (white square) along the upper reaches of a shallow drainage that flows to the north.

## The PB-Piedmont viewing domain and observation sites for 8 March 2006. Six observation sites collocated by pairs are found northwest of the burn site (white square).

## The plume structure at 1900 EST, 36 minutes after sunset. Strong synoptic forcing pushes smoke to the north with no apparent drainage effects of the shallow stream valleys.

## 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, 8 March 2006.

- 2: Slight smoke (2130)

- 3: Light smoke (2138)

- Click left mouse button to view observation points.

## Summary: 2130 Observations

- Observations taken from 2130-2138 were compared with the 2200 PB-Piedmont simulation.
- PB-Piedmont correctly placed smoke at 2 of the 2 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 0000 EST, 9 March 2006

- 4: Slight smoke (2330)

- 5: Slight smoke (2345)

- Click left mouse button to view observation points.

## Summary: 0100 Observations

- Observations taken from 2330- 2345 EST were compared with the 0000 PB-Piedmont simulation.
- PB-Piedmont correctly placed smoke at 2 of the 2 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 0600 EST, 9 March 2002.

- 6: Slight smoke (0550)

- 7: No smoke (0600)

- Click left mouse button to view observation points.

## Summary: 0600 Observations

- Observations taken from 0550- 0600 EST were compared with the 0600 PB-Piedmont simulation.
- PB-Piedmont correctly placed smoke or no smoke at 1 of the 2 observation sites.

## Summary:

- PB-Piedmont correctly placed smoke or no smoke at 5 of the 6 observation sites.

## Smoke Matrix

- Smoke Prediction

- Yes                 No

- Smoke Observation

-   No                Yes

- 5

- 0

- 1

- 0