Download - P9 Fire-Atmosphere Interactions During Low-Intensity ... · Fire-Atmosphere Interactions During Low-Intensity Prescribed Fires in the New Jersey Pine Barrens Warren E. Heilman1, Xindi

Fire-Atmosphere Interactions During Low-Intensity Prescribed Fires in the New Jersey Pine Barrens

Warren E. Heilman1, Xindi Bian1, John L. Hom2, Kenneth L. Clark3, Nicholas S. Skowronski4, Michael Gallagher3, Matthew Patterson2, Yonqiang Liu5, Ken Forbus5, Christie Stegall5, Joseph J. Charney1, Shiyuan Zhong6, Michael T. Kiefer6, Bob Kremens7

1USDA Forest Service, East Lansing, MI; 2USDA Forest Service, Newtown Square, PA; 3USDA Forest Service, Silas Little Experimental Forest, NJ;

4USDA Forest Service, Morgantown, WV; 5USDA Forest Service, Athens, GA; 6Michigan State University, East Lansing, MI; 7Rochester Institute of Technology, Rochester, NY

Study Objectives

• Develop a comprehensive monitoring

network within and in the vicinity of prescribed burn blocks in the New Jersey Pine Barrens to measure fire-atmosphere interactions and local air quality during low-intensity fires.

• Examine the impacts of forest overstory vegetation on atmospheric circulations, thermal fields, and the transport and dispersion of smoke in forested environments during low-intensity fires.

• Use the observational data to evaluate meteorological and atmospheric dispersion modeling systems applied to low-intensity fires in forested environments.

Study Locations

Monitoring networks were established within and near two relatively flat burn blocks located in the Brendan T. Byrne State Forest in central New Jersey. Burn experiments (surface fires) were conducted on 20 March 2011 and 6 March 2012. Vegetation in each block consisted of ~15-18 m pitch-pine/mixed-oak overstory and Vaccinium/scrub-oak understory. Surface Fuel Loading Experiment E1: 1478 g m-2 Experiment E2: 1104 g m-2

6 March 2012 Experiment E2

20 March 2011 Experiment E1

Monitoring Networks and Prescribed Burn Patterns N

N

20 March 2011

6 March 2012

265 acres

240 acres

A series of 3 m, 10 m, 20 m, and 30 m towers and surface stations were set up within and outside each burn block and instrumented with a variety of monitoring equipment to measure high frequency (0.5-10 Hz) wind speeds, wind directions, temperatures, relative humidity, radiative heat fluxes, pressure, turbulent heat and momentum fluxes, net radiation, and CO, CO2, and PM2.5 concentrations during backing prescribed fires that burned through each burn block. Additional measurements included fuel loading, fuel moisture, ceilometer-based plume heights, LIDAR-based vegetation structure, and aerial IR imagery of the burns.

Location of towers and surface monitoring stations in each burn block for the E1 (20 March 2011) and E2 (6 March 2012) prescribed burn experiments. 3 m towers: yellow circles; 10 m towers: blue circles; 20 m towers: purple circles; 30 m towers: red circles; 10 m control towers: green circles; PM2.5 monitors: brown diamonds; ceilometer: blue star; remote helicopter: pink square.

NE to SE ambient wind directions during the burn

N to SW ambient wind directions during the burn

Tower Instrument Variable Measurement

Height (m AGL) Sampling

Frequency

3 m

Thermocouples (Omega XC-24-K-12 @ 0 m) (Omega SSRTC-GG-K-36-36)

Temperature 0, 1, 3 0.5 Hz

CO Sensors (Figaro TGS5042)

CO conc. 3 0.5 Hz

Anemometers (E2 only) (Davis Instruments DV6410)

Mean wind speed and direction

3 0.5 Hz

Temperature/RH probes (EME Systems SHT75PG)

Mean temperature and RH

2 0.5 Hz

10 m

3D sonic anemometers (R.M. Young 81000V)

u, v, w, t 3, 10 10 Hz

Temperature/RH probes (Vaisala HMP50)


3, 10 10 HZ

Thermocouples (Omega SSRTC-GG-K-36-36)

Temperature 0, 1, 2, 3, … 10 10 Hz


CO conc. 3, 10 10 Hz

CO2 Sensor (Vaisala GMM222E)

CO2 conc. 5 10 Hz

Radiative Heat Flux Sensor (Medtherm 64-20-20)

Radiative heat flux 4.5 10 Hz

Barometer (Viasala PTB 110)

Pressure 7 10 Hz

Soil thermocouples (Omega XC-24-K-12: Litter)

(Omega KMQLX-032-6) Temperature Litter, -0.10, -0.20 10 Hz

20 m


u, v, w, t 3, 10, 20 10 Hz



3, 10, 20 10 HZ

Thermocouples (Omega SSRTC-GG-K-36-36)

Temperature 0, 1, 2, 3, … 10, 12.5,

15, 17.5, 20 10 Hz


CO conc. 3, 10, 20 10 Hz

CO2 Sensor (Vaisala GMM222E)

CO2 conc. 5 10 Hz

Radiative Heat Flux Sensor (Medtherm 64-20-20)

Radiative heat flux 4.5 10 Hz

Barometer (Vaisala PTB110)

Pressure 11 10 Hz

Soil thermocouples (Omega XC-24-K-12: Litter)

(Omega KMQLX-032-6) Temperature Litter, -0.10, -0.20 10 Hz

30 m


u, v, w, t 3, 10, 30 10 Hz



3, 10, 30 10 HZ

Thermocouples (Omega SSC-TT-T-36-36)

Temperature 0, 1, 2, 3, … 10, 12,

16, 20, 25, 30 10 Hz


CO conc. 3, 10, 30 10 Hz

CO2 Sensor (LI-COR 820)

CO2 conc. 5 10 Hz

Net radiometer (Kipp and Zonen NR-Lite)

Net radiation 30 10 Hz

Barometer (Vaisala PTB110)

Pressure 2.1 10 Hz

Soil thermocouples (Omega KMQLX-032-6)

Temperature -0.02, -0.20 10 Hz

10 m Control


u, v, w, t 3, 10 10 Hz



3, 10 10 HZ

Thermocouples (Omega SSC-TT-T-36-36)

Temperature 0, 1, 2, 3, … 10 10 Hz


CO conc. 3, 10 10 Hz

CO2 Sensor (Li-Cor 820)

CO2 conc. 5 10 Hz

Net radiometer (Kipp and Zonen NR-Lite)

Net radiation 2 10 Hz

Barometer (Viasala PTB110)

Pressure 1.5 10 Hz

Soil thermocouples (Omega TMQSS-032U-6)

Temperature -0.02, -0.20 10 Hz

Aerial LIDAR imagery of forest floor elevation differences between burned and unburned areas at 1715 EDT on 20 March 2011. Image shows the general backing fire line progression to the NE through the burn block, starting with an initial fire line ignition along the western border of the burn block (~0955- EDT).

N

Initial ignition point at ~0955 EDT

Burned area

Unburned area

Direction of fireline progression

N

Aerial visual and IR imagery of smoke and individual fire lines progressing to the W through the burn block at 1210 EST on 6 March 2012. Initial fire line was ignited along the eastern border of burn block between ~0930-1030 EST.

N

Direction of fireline progressions

Summary of the instrumentation and monitoring protocols used at the 3 m, 10 m control, 10 m, 20 m, and 30 m towers for the E1 (20 March 2011) and E2 (6 March 2012) prescribed burn experiments.

Key Conclusions and Next Steps

Photographs Temperatures at 20 m Tower

March 2011 Fractional Day (UTC)

20.76 20.78 20.80 20.82 20.84 20.86

Tem

pera

ture

(C

)

0

10

20

30

40

50

60

70

20 m AGL

10 m AGL

3 m AGL

1443:12 1512:00 1540:48 1609:36


6.82 6.84 6.86 6.88 6.90 6.92

Te

mp

era

ture

(C

)

0

10

20

30

40

50

60

70

20 m AGL

10 m AGL

3 m AGL

1509:36 1538:24 1607:12 1636:00

Temperature (C)

0 5 10 15 20 25 30 35 40 45 50 55 60 65

He

igh

t (m

)

0

2

4

6

8

10

12

14

16

18

20

1516 EDT

1517 EDT

1518 EDT

1519 EDT

1520 EDT

Temperature (C)

0 5 10 15 20 25 30 35 40 45 50 55 60 65

He

igh

t (m

)

0

2

4

6

8

10

12

14

16

18

20

1521 EDT

1522 EDT

1523 EDT

1524 EDT

1525 EDT

Temperature (C)

0 5 10 15 20 25 30 35 40 45 50 55 60 65

He

igh

t (m

)

0

2

4

6

8

10

12

14

16

18

20

1526 EDT

1527 EDT

1528 EDT

1529 EDT

1530 EDT

Temperature (C)

0 5 10 15 20 25 30 35 40 45 50 55 60 65

He

igh

t (m

)

0

2

4

6

8

10

12

14

16

18

20

1535 EST

1536 EST

1537 EST

1538 EST

1539 EST

Temperature (C)

0 5 10 15 20 25 30 35 40 45 50 55 60 65

He

igh

t (m

)

0

2

4

6

8

10

12

14

16

18

20

1540 EST

1541 EST

1542 EST

1543 EST

1544 EST

Temperature (C)

0 5 10 15 20 25 30 35 40 45 50 55 60 65

He

igh

t (m

)

0

2

4

6

8

10

12

14

16

18

20

1545 EST

1546 EST

1547 EST

1548 EST

1549 EST

Wind Speeds and Turbulence at 20 m Tower


20.76 20.78 20.80 20.82 20.84 20.86

Sp

ee

d (

m s

-1)

-6

-5

-4

-3

-2

-1

0

1

2

3

4

20 m AGL

10 m AGL

3 m AGL

1443:12 1512:00 1540:48 1609:36


20.76 20.78 20.80 20.82 20.84 20.86

Sp

ee

d (

m s

-1)

-4

-3

-2

-1

0

1

2

3

4

5

6

20 m AGL

10 m AGL

3 m AGL

1443:12 1512:00 1540:48 1609:36


20.76 20.78 20.80 20.82 20.84 20.86

Sp

ee

d (

m s

-1)

-2

-1

0

1

2

3

20 m AGL

10 m AGL

3 m AGL

1443:12 1512:00 1540:48 1609:36


6.82 6.84 6.86 6.88 6.90 6.92

Sp

ee

d (

m s

-1)

-4

-3

-2

-1

0

1

2

3

4

5

6

20 m AGL

10 m AGL

3 m AGL

1509:36 1538:24 1607:12 1636:00


6.82 6.84 6.86 6.88 6.90 6.92

Sp

ee

d (

m s

-1)

-4

-3

-2

-1

0

1

2

3

4

5

6

20 m AGL

10 m AGL

3 m AGL

1509:36 1538:24 1607:12 1636:00


6.82 6.84 6.86 6.88 6.90 6.92

Sp

ee

d (

m s

-1)

-2

-1

0

1

2

3

20 m AGL

10 m AGL

3 m AGL

1509:36 1538:24 1607:12 1636:00


20.76 20.78 20.80 20.82 20.84 20.86

TK

E (

m2s

-2)

0

5

10

15

20

25

20 m AGL

10 m AGL

3 m AGL

1443:12 1512:00 1540:48 1609:36


6.82 6.84 6.86 6.88 6.90 6.92

TK

E (

m2s

-2)

0

5

10

15

20

25

20 m AGL

10 m AGL

3 m AGL

1509:36 1538:24 1607:12 1636:00

Air Quality

Consumption: 689 g m-2

Consumption: 507 g m-2

0

100

200

300

400

500

600

700

800

PM1 PM2 PM3 PM4 30 mTower

Surface PM2.5 Monitors

Maximum PM2.5 Concentrations (μg m-3)

E1

E2

E1

E1

E2

E2

Example fire line and smoke conditions during the E1 (20 March 2011) and E2 (6 March 2012) burn experiments.

E1

E2

E1

E1

E1

E2

E2

E2

Observed temperature time series during fire front passage for the E1 and E2 experiments. EDT (E1) and EST (E2) times shown above x-axis.

Observed temperature profiles during fire front passage for the E1 and E2 experiments.

0

100

200

300

400

500

600

700

800

900

1 2 3 4 5 6 7 8 9 10 11 12

3 m Tower Number

Maximum CO Concentrations (ppm)

E1

E2

U

V

W

U

V

W

E1

E1

E1

E2

E2

E2

Observed east-west (U), north-south (V), and vertical (W) wind speed time series during fire front passage for the E1 and E2 experiments. EDT (E1) and EST (E2) times shown above x-axis. Dashed line indicates time of fire front passage.

E1

E2

Time-frequency wavelet spectrum of vertical wind speeds for the E1 and E2 experiments indicate prominent modes of variability before, during, and after fire front passage.

E1

E2

Turbulent Kinetic Energy

Turbulent Kinetic Energy

Observed turbulent kinetic energy during fire front passage for the E1 and E2 experiments. EDT (E1) and EST (E2) times shown below top axis.

E2

• Turbulent circulations in the vicinity of surface fires and the resulting horizontal and vertical dispersion of heat and smoke from those fires are not only affected by fire intensity, but also by the presence of forest overstory vegetation.

• Turbulent kinetic energy is most pronounced just above the canopy top, regardless of the presence of surface fires. • Overstory vegetation affects turbulence anisotropy and the directional mixing of heat, moisture, and smoke. • Meteorological and air-quality data from these experiments are being used to evaluate the ARPS-CANOPY/FLEXPART and

RAFLES modeling systems applied to low-intensity wildland fires in forested environments (JFSP Project 09-1-04-1). • Observational data will be uploaded to the Smoke Emissions Model Intercomparsion Project (SEMIP) data warehouse for

future model evaluation efforts.

Pmax= 304

Pmax= 132

1200 1400 1600 1800

1100 1300 1500 1700

EDT

EST

23 min

7.6 min

8 min

Observed PM2.5 and CO concentrations within and in the vicinity of the E1 and E2 burn blocks.

P9

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