Maria Val Martin and J. Logan (Harvard Univ., USA)

Maria Val Martin and J. Logan (Harvard Univ., USA)

D. Nelson, C. Ichoku, R. Kahn and D. Diner (NASA, USA)

S. Freitas (INPE, Brazil)

F.-Y. Leung (Washington State Univ., USA)

Research funded by NSF and EPA

Wildfire Plume Injection Heights Over North America: An Analysis

of MISR, MODIS and a 1-D Plume-rise Model

Outline An statistical analysis of aerosol injection heights

over North America The use of a 1-D plume-rise model to develop a

parameterization of the injection heights of North American wildfire emissions

Wildfire Plume Injection Heights Over North America: An Analysis

of MISR, MODIS and a 1-D Plume-rise Model

Multi-angle Imaging SpectroRadiometer- MISR

9 view angles at Earth surface: nadir to 70.5º forward and backward

4 bands at each angle:446, 558, 672, 866 nm

Continuous pole-to-pole coverage on orbit dayside

400-km swath9 day coverage at equator2 day coverage at poles

Overpass around local noon time in high and mid- latitudes

275 m - 1.1 km sampling

In polar orbit aboard Terra since December 1999

MISR Plumes: MISR INteractive eXplorer (MINX)

http://www.openchannelsoftware.org

Smoke plume over central Alaska on June 2002

Cross-section of heights as a function of distance from the source

Histogram of heights retrieved by MINX

About 3500 plumes digitalized over North America

20022004200520062007

http://www-misr2.jpl.nasa.gov/EPA-Plumes/

Plume Distribution, Atmospheric Conditions and Fire Properties

pcR

dz

d/

PT where,Stability

P0

•Meteorological fields from

GEOS-4 and GEOS-5 2x2.5

•Fire Properties from MODIS Fire Radiative Power

Histogram of Plume Height Retrievals Atmospheric Stability Profile

Max

Avg Median

Mode

Plume Height?

Each individual height

Stable Layer

Boundary Layer (BL)

Leung et at, PosterB31C-0302

5-30% smoke emissions are injected above the boundary

layer

Kahn et al, [2008]

Distribution of MISR heights-PBL for smoke plumes

2004

200210–25%

20054–15%

20069–28%

20079–18%

Val Martin et al, in preparation

Tropical Forest

Cropland

Temperate Forest

Boreal Forest

Boreal Shrub

Non-Boreal Shrub

Boreal Grassland

Non-Boreal Grassland

Vegetation type based on MODIS IGBP land cover map

(http://modis-land.gsfc.nasa.gov/landcover.htm)

1x1 kmresolution

Classification of plume distribution by vegetation type

Percentage of smoke above BL varies with vegetation type and fire season

2002

2004200520062007

% Height retrievals with [Height-PBL] > 0.5 km

Number of plumes

Close relationship between plume distribution, fire intensity and fire size

Plume Height versus Fire Intensity

Plume Height versus Fire Size

Fire intensity drives the interannual variability of plume heights

20022004200520062007

Distribution of MISR heights and MODIS FRP by year

200

200

Also, fire intensity drives the seasonality of plume heights

Boreal Forest2002 and 2004-2007

1-D Plume-resolving Model

Detailed information in Freitas et al, [2007]

Key input parameters:•Instant fire size: MODIS FRP (max FRP observed in each biome 1 km2 burned [Charles Ichoku, personal communication])

•Total heat flux: Max MODIS FRP observed over vegetation type x 10 [Wooster et al, 2005; Freeborn et al., 2008]

•RH, T, P, wind speed and direction: from GEOS-4 meteo fields 2x2.5

• Fuel moisture content: from the Canadian Fire Weather Model

Simulation of a boreal fire plume in Alaska and a grassland fire plume in Mexico

Fire Size= 300 HaHeat Flux= 18 kW/m2

Fire Size= 3.3 HaHeat Flux= 9 kW/m2

MISR Retrieved HeightsMISR Smoke Plume 1D Plume-rise Model

Boreal Forest Fire

Grassland Fire

Simulation of a boreal fire plume in Alaska and a grassland fire plume in Mexico

Fire Size= 300 HaHeat Flux= 18 kW/m2

Fire Size= 3.3 HaHeat Flux= 9 kW/m2

MISR Retrieved HeightsMISR Smoke Plume 1D Plume-rise Model

Boreal Forest Fire

Grassland Fire

5025 m 5425 m

1200 m

900 m

The 1-D Plume-resolving Model simulates fairly well the observed MISR heights

Correlation between simulated plume heights and MISR observed heights over North America

2688N0.40r

25.0Int1.84) -(0.73 1.15slope

2

All Plumes

5-30% of smoke emissions are injected above the BL.

The percentage of smoke that reaches the FT depends on fire characteristics (e.g., vegetation type, fire intensity, etc) and year-to-year variations .

Fire intensity drives the seasonality and interannual variability of the plume heights.

1-D plume-resolving model simulates fairly well the observed MISR plume heights.

In the future, we plan to embed the 1-D plume-resolving model with GEOS-Chem to simulate vertical transport of North American wildfire emissions.

Concluding Remarks

Extra Slides



677N0.31r

43.0Int1.91) -(0.59 1.06slope

2

Boreal Forest Plumes



309N0.53r

06.0Int1.75) -(0.93 1.28slope

2

Temperate Forest Plumes

Model simulated heights versus MISR observed heights by year

Model simulated heights versus MISR observed heights by vegetation

Smoke emissions tend to get confined within stable layers in the atmosphere, when they

exist

11% 13% 7% 24%13%

Distribution of all individual heights in the FT – Stable Layer

MISR Height – Stable Layer Height ≈ 0 km

Relationship between simulated heights and 1-D model input parameters

The 1D plume-resolving model: Governing equations

dynamics

thermodynamics

water vapor conservation

bulk microphysics

cloud water conservation

rain/ice conservation

The 1D plume-resolving model: The lower boundary conditions

Intensity of the fire drives the interannual variability of plume heights


Trop Forest


Temperate Forest


Boreal Shrub


Boreal Grassland


NonBoreal Grassland


Cropland

Maria Val Martin and J. Logan (Harvard Univ., USA)

Documents

Transcript of Maria Val Martin and J. Logan (Harvard Univ., USA)