Investigations of Plumes from Biomass Burning using ATHAM

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Investigations of Plumes from Biomass Burning
using ATHAM

• Jörg Trentmann
• Gunnar Luderer, Christiane Textor, Michael
  Herzog, Tanja Winterrath, Hans-F. Graf, Meinrat
  O. Andreae

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• Overview
• Introduction Fires and their smoke plumes,
  pyro-clouds
• Scientific questions and limitations of
  large-scale models
• Recent studies using ATHAM
• vertical transport
• chemical processes
• Potential for future investigations

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• Vegetation fires occur all over the globe, mostly
  in the tropics.
• Emissions from fires consist of gaseous, CO2,
  CO, NOx,VOCs, and particulate, mainly organic and
  black carbon (OC/BC), compounds.
• Also heat and water vapor is emitted, leading to
  fire-induced convection.

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Burning of logging residues, US Pacific Coast,
September 1994 Quinault Fire
Photo by R. Ottmar
Picture based on AVIRIS data
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Bor Fire, Siberia, 199450 ha prescribed fire
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Alaskan Fire, June 2004
Photograph taken from a commercial aircraft on
its way to Japan.
Picture courtesy of Mr N. Todo,Japan Airlines
International Co. Ltd.
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Deforestation fire, Brazil, 2000
Photo by Axel Thielmann
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What is happening in smoke plumes and does it
matter?
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Emissions from Biomass Burning produce
Tropospheric Ozone
Climatological tropospheric ozone, October
Fishman et al., ACP, 2003
On the annual and global scale about 10 of the
ozone production is related to biomass burning,
locally this value is substantially
higher. Marufu et al., JGR 2000
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(No Transcript)
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Particulate Emissions
California Fires, 26 October 2003 Aqua MODIS
Half of the global emissions of black carbon (BC)
are attributed to biomass burning. Ramanathan et
al., Science, 2001
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Global atmospheric chemistry and/or aerosol
models consider emissions from biomass burning

• estimate the burned fuel based on satellite
  observations of number of fires or burned area
• use of emission factors based on field and lab
  measurements
• derive gridded emission field (1 x 1 deg,
  monthly), e.g. Duncan et al., 2003 van der Werft
  et al., 2003 Hoelzemann et al., 2004 Ito et
  al., 2004

Galanter et al., 2000
On the global scale the primary ( unprocessed)
emissions are usually deposited into the lowest
( no vertical transport) grid box with a
horizontal size of about 1 x 1 deg ( immediate
dilution of the emissions).
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Local small-scale processes affect the regional
and global atmospheric impact of fires

• Vertical transport of the primary fire emissions
• Cloud processing of the smoke particles and
  gaseous emissions, e.g., scavenging
• Photochemistry leading to the production of
  ozone, oxidation of hydrocarbons

These processes should be incorporated into the
parameterisations used in large scale models to
describe the emissions from biomass burning!
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Smoke plumes and pyro-clouds as natural
laboratories for the study of atmospheric
processes

• Dynamics of convective clouds
• Aerosol-cloud interaction in convective clouds
  potential CCN, IN impact on precipitation,
  lightning
• Atmospheric photochemistry

Detailed studies of fire plumes increase our
understanding of fundamental atmospheric
processes!
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ATHAM is an excellent tool to investigate the
small-scale processes in smoke plume and
pyro-clouds!

• Effective treatment of the dynamical aspects of
  intense convective events in three dimensions
• High spatial resolution (down to 50 m, i.e., LES
  scale)
• Modules for the turbulence, cloud microphysics(,
  and chemistry)
• Fire emissions- user-defined temporal and
  spatial distribution- heat, moisture (, aerosol
  mass, CO2, CO, VOCs, NOx.....) via
  emission ratios- no feedback between atmosphere
  (e.g., wind field) and fire emissions

Previous studies of smoke plumes conducted with
ATHAM

• Quinault fire Transport, Radiation, Chemistry
• Chisholm fire Transport into the stratosphere

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Transport of the Quinault Fire Plume Comparing
model simulations with observations
Strong temperature inversion at about 600 m,low
humidity
21 September 1994 1100 LT
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Airborne LIDAR measurement University of
Washington Hobbs et al., 1996

• vertical extend of the plume limited by the
  inversion
• slow downwind lofting of the plume

• Model results in reasonable agreement with
  observations
• downwind lofting is not reproduced, solar heating
  of the smoke aerosol is included in the model and
  not sufficient,maybe sea breeze effect

Trentmann et al., 2002
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Investigation of plume photochemistry
Observations from the Quinault plume yield low
ozone concentrations above the fire and enhanced
ozone downwind.
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Chemistry module in ATHAM

• Describes the atmospheric oxidation of
  hydrocarbons emitted by fires and the formation
  of ozone and other secondary compounds under the
  conditions in young smoke plumes (i.e., high NOx
  concentrations)
• Technical realisation based on the Kinetic
  PreProcessor (KPP)1, that allows flexible
  modifications of the chemical reactions
• Presently not actively in use and not supported,
  but can be reactivated

1 Sandu et al., 2003, available at
http//people.cs.vt.edu/asandu/
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Chemical simulation of the Quinault fire plume
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The Chisholm Fire
28/29 May 2001, Alberta, Canada
Transport of smoke into the stratosphere
Pyro-cloud with overshooting top
Location of Fire
AVHRR false color image, 29 May 2001, 0200 UTC
Fromm and Servranckx, 2003
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ATHAM results aerosol mass concentration
Potential temperature on 100 µg/m³ aerosol
isosurface
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ATHAM results Hydrometeors
Simulated isosurface of the mass concentration
(0.4 g m-3) of the different classes of
hydrometeors. Blue small liquid, purple large
liquid, yellow small frozen, orange large
frozen, red aerosol.
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ATHAM has been used successfully for the
simulation of the dynamical and chemical aspects
in young smoke plumes. Future studies using
ATHAM combined with field observations will
improve our current understanding of the
underlying processes.

• Selected open scientific questions
• Which conditions (fire and meteorological) are
  required to transport smoke into the upper
  troposphere and the lower stratosphere?
• What is the role of the smoke aerosol in the
  formation and evolution of the pyro-convection?
• Which fraction of the primary emitted smoke is
  deposited into the atmosphere?
• How significant is smoke plume chemistry for the
  larger scale impact of biomass burning emissions?

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ATHAM will be used to improve the representation
of fire emissions in larger scale models.

• Improving the assumptions of the emission height
  of fire emissions towards a more mechanistic
  description including the dependence on fire size
  and/or meteorological conditions.
• Deriving effective emissions that include local
  effects which are not resolved by large-scale
  models, e.g., formation of ozone, scavenging of
  smoke particles.

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Numerous interesting scientific questions related
to small-scale processes in the plumes from
vegetation fires with ATHAM are waiting to be
addressed!
Lets do it!!