Wildfire Plume Injection Heights Over North America An

Wildfire Plume Injection Heights Over North America: An Analysis of MISR, MODIS and a 1 -D Plume-rise Model 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 ü An statistical analysis of aerosol injection heights over North America ü The use of a 1 -D plume-rise model to develop a parameterization of the injection heights of North American wildfire emissions

Multi-angle Imaging Spectro. Radiometer- 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 swath 9 day coverage at equator 2 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 e. Xplorer (MINX) Smoke plume over central Alaska on June 2002 Cross-section of heights as a function of distance from the source http: //www. openchannelsoftware. org Histogram of heights retrieved by MINX

About 3500 plumes digitalized over North America 2002 2004 2005 2006 2007 http: //www-misr 2. jpl. nasa. gov/EPA-Plumes/

Plume Distribution, Atmospheric Conditions and Fire Properties Histogram of Plume Height Retrievals Atmospheric Stability Profile Plume Height? Leung et at, Poster B 31 C-0302 Max Avg Median Stable Layer Mode Boundary Layer (BL) Each individual height • Meteorological fields from GEOS 4 and GEOS-5 2 x 2. 5 • Fire Properties from MODIS Fire Radiative Power

5 -30% smoke emissions are injected above the boundary layer 2004 2002 10– 25% 2006 9– 28% 2005 4– 15% 2007 9– 18% Kahn et al, [2008] Distribution of MISR heights-PBL for smoke plumes Val Martin et al, in preparation

Classification of plume distribution by vegetation type Vegetation type based on MODIS IGBP land cover map Cropland Non-Boreal Grassland Non-Boreal Shrub Boreal Forest Temperate Forest 1 x 1 km resolution (http: //modis-land. gsfc. nasa. gov/landcover. htm) Tropical Forest

Percentage of smoke above BL varies with vegetation type and fire season 2002 2004 % Height retrievals with [Height-PBL] > 0. 5 km 2005 2006 2007 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 Distribution of MISR heights and MODIS FRP by year 2002 2004 2005 2006 2007

Also, fire intensity drives the seasonality of plume heights Boreal Forest 2002 and 2004 -2007 200

1 -D Plume-resolving Model Key input parameters: • Instant fire size: MODIS FRP (max FRP observed in each biome 1 km 2 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] Detailed information in Freitas et al, [2007] • RH, T, P, wind speed and direction: from GEOS 4 meteo fields 2 x 2. 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 MISR Smoke Plume Boreal Forest Fire Size= 300 Ha Heat Flux= 18 k. W/m 2 Grassland Fire Size= 3. 3 Ha Heat Flux= 9 k. W/m 2 MISR Retrieved Heights 1 D Plume-rise Model

Simulation of a boreal fire plume in Alaska and a grassland fire plume in Mexico MISR Smoke Plume Boreal Forest Fire MISR Retrieved Heights 5025 m 1 D Plume-rise Model 5425 m Fire Size= 300 Ha Heat Flux= 18 k. W/m 2 Grassland Fire 1200 m 900 m Fire Size= 3. 3 Ha Heat Flux= 9 k. W/m 2

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 All Plumes

Concluding Remarks Ø 5 -30% of smoke emissions are injected above the BL. Ø The percentage of smoke that reaches the FT depends on fire characteristics (e. g. , vegetation type, fire intensity, etc) and year-to-year variations. Ø Fire intensity drives the seasonality and interannual variability of the plume heights. Ø 1 -D plume-resolving model simulates fairly well the observed MISR plume heights. Ø 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.

Extra Slides

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 Boreal Forest Plumes

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 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 MISR Height – Stable Layer Height ≈ 0 km Distribution of all individual heights in the FT – Stable Layer 11% 13% 7% 24% 13%

Relationship between simulated heights and 1 -D model input parameters

The 1 D plume-resolving model: Governing equations dynamics thermodynamics water vapor conservation cloud water conservation rain/ice conservation bulk microphysics

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

Intensity of the fire drives the interannual variability of plume heights

Also, fire intensity drives the seasonality of plume heights Trop Forest

Also, fire intensity drives the seasonality of plume heights Temperate Forest

Also, fire intensity drives the seasonality of plume heights Boreal Shrub

Also, fire intensity drives the seasonality of plume heights Boreal Grassland

Also, fire intensity drives the seasonality of plume heights Non. Boreal Grassland

Also, fire intensity drives the seasonality of plume heights Cropland