1. Terra Observations of Tropospheric Aerosol and CO from Biomass Burning
David Edwards, Xuexi Tie, Louisa Emmons, and John Gille
National Center for Atmospheric Research, Boulder CO, USA
Allen Chu and Yoram Kaufman
NASA Goddard Space Flight Center, Greenbelt MD, USA

2. Biomass Burning: Impacts on Tropospheric Chemistry and Climate
Approximately half-billion hectares of natural and human-induced biomass burning occurs each year
In tropical regions, biomass burning for cultivation, deforestation and savanna grazing is a major forcing mechanism for tropospheric photochemistry
Fires emit large amounts of aerosol, CO, and hydrocarbons which strongly affect tropospheric O3 and the oxidising capacity of the atmosphere
In addition to a climatic impact that is not well quantified, this also has implications for weather modification and air quality
David Edwards, NCAR

3. Sept. 2000
MODIS Aerosol
MODIS can distinguish between coarse and fine particles using multiple channels from the visible to the near IR
Course aerosol mode: Mainly dust and sea salt
Reflects in the VIS & NIR: Appears red in the VIS due to absorption in the blue
Surface characterization is an issue over land
Fine aerosol mode: Anthropogenic pollution and biomass burning
Reflects mainly in the VIS
Coarse mode
(AOD)
Fine Mode
David Edwards, NCAR

4. MODIS Aerosol & MOPITT CO Sept. 2000
Good correlation is obtained between MODIS fine mode AOD & MOPITT CO
Both CO and fine mode aerosol result from anthropogenic combustion processes: urban pollution, industry, and tropical biomass burning
Fine Mode AOD
MOPITT
CO Column
David Edwards, NCAR

5. South African & South American Plumes
Southern African burning is a maximum in Sept.-Oct.
Anti-cyclonic winds in southern Africa and the southern Atlantic result in strong re-circulations
A stable mixing layer over Africa provides containment for several days
Part of the African plume is advected into the Atlantic
Periodically, the plume is advected south-east and caught in the westerly flow at higher southern latitudes
Ten day trajectories starting using HYSPLIT
This an important mechanism providing for the long-range export of emissions
In Brazil, strong convection lifts emissions to the mid troposphere
The South American plume is advected south-east across the Atlantic
The Atlantic becomes crossed by plumes moving in opposite directions
David Edwards, NCAR

6. Prescribed burn near Kruger National Park, South Africa, September 7, 2000.
Photo from the Convair (Flight 1834) during SAFARI by Peter Hobbs, UWA.
SeaWiFS true-color image acquired over Southern Africa, September 4, Data acquired by the Satellite Applications Center, Pretoria, South Africa.
David Edwards, NCAR

7. MODIS Fine Mode AOD
MOPITT 700 hPa CO
AOD/CO Ratio
Plume aging can be followed as the AOD/CO ratio falls, indicating persistent CO but reduced aerosol loadings due to the shorter aerosol lifetime
David Edwards, NCAR

8. MOPITT CO total column, Oct. 1-15, 2000
Providing global context to local measurements: Long-range transport of biomass burning products
October 1-15, 2001
MOPITT and ground-based FTIR CO total column measurements taken at Lauder, New Zealand.
The plume from biomass burning causes a peak in the measured CO in the usually clean air over New Zealand
FTIR data: N. Pougatchev, NASA & N. Jones, NIWA
David Edwards, NCAR

9. MODIS AOD
Fine Mode
MOPITT CO
Total Column
David Edwards, NCAR

10. GOME NO2 Tropospheric Residual MOPITT CO Column
TRMM/VIRS Fire Counts
MODIS Fine Mode AOD
GOME NO2 Tropospheric Residual
MOPITT CO Column
Satellite Observations of Biomass Burning and Resultant Plumes: Sept. 2000
Andreas Richter, U. Bremen
David Edwards, NCAR

11. Effect of Aerosol on Ozone Production
J[NO2]
J[O3]
Clear Sky
BC Layer
Effect of Aerosol on Ozone Production
Black carbon from biomass burning strongly absorbs solar radiation and can potentially reduce photolysis rates within biomass burning plumes
Reduction in photolysis can lead to a compensating offset to the expected increase in O3 production due to the higher concentrations of NOx, CO, and other hydrocarbons
Heterogeneous reactions on BC particles can also affect O3 concentrations and the uptake coefficient for O3 on BC particles remains uncertain
TUV photolysis rate calculation in a BC layer of AOD at 340 nm of 0.5 in the lowest 3km of the atmosphere
David Edwards, NCAR

12. Summary
The combination of measurements from the new tropospheric satellite sensors will play an increasingly important role in explaining chemistry and transport processes in the lower atmosphere
This will be complimentary to continued in-situ measurements and modeling for sensitivity and process studies
MOPITT CO and MODIS fine/coarse particle measurements can be combined to examine the seasonal variability and transport of aerosols and trace gases in biomass burning plumes
Provides information about continental export and the impact of intense fire sources on global scale air quality
Variations in plume relative composition for different burning regimes might potentially provide information about emission factors
Detailed examination of O3 precursor emissions and transport, and the effect of BC on photolysis and heterogeneous chemistry is still required to quantify the impact on the tropical tropospheric O3 distribution
David Edwards, NCAR