Vegetation fires are a significant source of atmospheric trace gases and aerosol particles (AP) on both local and global scale. Vast fires regularly occur in the tropics (Africa, South America, and South East Asia) as well as in the mid latitudes and boreal regions (the Mediterranean region, USA (Fig. 1), Canada, Scandinavia, and Russia).

The EFEU community is interested mainly in the cloud relevant and radiative properties of biomass burning aerosol on a broad range of scales. This includes phenomena such as warm rain suppression as well as the evolution of individual biomass burning clouds. Direct and indirect radiative effects are investigated.

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METHODS

EFEU combined experimental and numerical research drawing from the expertise of eight different research groups. The experimental part was designed to enhance the database on biomass burning emissions with a particular focus on the suite of input parameters required by the numerical models employed in the EFEU project. Three series of laboratory experiments in 2002 and 2003 were performed with various types of typical biomass burning fuel ranging from central European to tropical fuel types. During these experiments physical, optical, and chemical particulate parameters as well as CO, CO2 and NO were characterized.

Among the measurement parameters were:

• optical absorption and scattering coefficients of aerosol particles
  
• total particle concentration and number size distribution
  
• morphological characterization by single particle analysis
  
• size resolved chemical characterization of particulate matter
  
• hygroscopic growth factors of the particles and CCN/CN ratios
  
  

A hierarchically structured suite of originally independent numerical models was employed to investigate the complex impact of biomass burning emissions on the atmosphere. The various model components complement each other addressing different aspects of this topic on a range of spatial and temporal scales. Combined with the input data from the laboratory experiments this integrated approach allows a more complete view on physical, chemical and dynamical aspects of biomass burning plumes. The model hierarchy facilitates seamless transition from microscale to regional scale models and spans the temporal scale from a few minutes to months and years.

POLITICS

A variety of results can be expected from the suggested joint project. For the first time a complete characteri-zation of the aerosols emitted by vegetation burns is aimed at. These results will lead to an enhanced under-standing of the effects of fires on the composition and circulation of the atmosphere. They can be directly used by the different models involved in the project. The model studies in turn will lead to a significant increase in the understanding of the coupled processes of the vertical transport, the trace constituents and energy cycles from ground level to the upper troposphere. These results can be employed in other fields, like e.g. cloud induced convection. The development and application of several different detailed microphysical models allows one to build up a model hierarchy, which can be employed for many different fields of atmospheric research. Especially the development of parameterizations for cloud aerosol interactions which can be used in large scale models is a benefit for further research. Especially the fields of global climate modeling, climate risk assessment and the modeling of the global water budget will benefit from the expected results and model developments.

Furthermore the expected results can contribute to the development of tools to increase the safety of air traffic. A better knowledge of the clouds, the humidity profiles and the vertical transport in the vicinity of vegetation fires are important aspects for the safety of air traffic considering of wing icing of aircrafts and the occurrence of atmospheric turbulences.

Another important field in which the models and expected research results could be helpful, is disaster prevention. One point of major interest is the propagation of the smoke clouds in order to initiate evacuations in time and to minimize the risk for fire fighters. Furthermore it is important to know whether precipitation in the vicinity of fires can be expected to prevent further spread of the fires. In addition these aspects are also important for the risk assessment and the risk related damages and therefore important for insurance companies.

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CONTRIBUTIONS OF THE JOINT PROJECT TO THE GOALS OF THE ATMOSPHERIC RESEARCH PROGRAM 2000 (AFO2000)

The suggested joint project is related to the research focus A of the goals of the Atmospheric Research Program 2000. In more detail, it is planned to contribute to the following aspects:

1. Vertical transport in the troposphere: interactions between vertical transport processes in the planetary boundary layer and the atmospheric trace constituents and water budget, transport processes between the planetary boundary layer and the free troposphere with focus on cloud formation and the radiation budget.

2. Multiphase processes in the troposphere and stratosphere: determination of the temporal and spatial behavior of different aerosol types in the troposphere, their chemical characteristics, prognosis of the optical properties of the particles dependent on their composition and the particle structure, growth of aerosols and their physico-chemical modification by clouds, modification of relevant cloud processes and properties by aerosols.

3. Treatment of multiphase chemistry in Chemical-Transport Models (CTM). Coupling of models with different resolutions in time and space. Coupling between mass describing CTM and number dependent aerosol processes (e.g. cloud formation).

PRINCIPAL INVESTIGATOR

Dr. Martin Simmel (until summer 2003: Dr. Sabine Wurzler)
Institute for Tropospheric Research, Leipzig
simmel@tropos.de

PROPOSED PROJECT DURATION

01.04.2001 - 31.12.2004

ACKNOWLEDGEMENT

This research is supported by BMBF (AFO 2000 atmospheric research program, project 07AFT47).

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COOPERATION

Cooperation with AFO 2000 groups

• MODMEP
• 4DWOLKEN
• CARBAERO
• ECHO

National and international cooperation with

• A. Bott, University of Bonn, Institute for Meteorology
• A. Khain, Hebrew University, Jerusalem, Israel
• A. Massling, Institut für Troposphärenforschung, Leipzig
• B. Sierau, Institut für Troposphärenforschung, Leipzig
• C. Neusüss, Bruker saxonia Analytik GmbH, Leipzig
• K. Diehl, Institut für Troposphärenforschung, Leipzig
• K. Lehmann, Institut für Troposphärenforschung, Leipzig
• M. A. Box, School of Physics, University of New South Wales, Sydney, Australia
• P. Hobbs, University of Washington, Seattle, USA
• R. Bruintjes, NCAR, Boulder, CO, USA
• R. McGraw and D. Wright, BNL, Brookhaven, USA
• R. Ottmar and S. Ferguson, Fire and Environmental Research Applications Team (FERA), Seattle Forestry Sciences Lab, USA
• R. Posselt, Institut für Troposphärenforschung, Leipzig
• S. deFreitas, Citate Universitaria, Sao Paulo, Brasil
• Y. Kaufmann, NASA Goddard Space Flight Center, Greenbelt, USA
• Z. Levin, Tel Aviv University, Israel
  

DOWNLOADS

Pressemitteilung (März 04) zum AFO-Abschluss-Symposium über das Projekt EFEU - Vegetationsfeuer - Aerosole - Wolken - Niederschlag (Deutsch, März 2004; 101 KB)	- 2 pages
Impact of Vegetation Fires on Composition and Circulation of the Atmosphere (EFEU) / Sabine Wurzler, Martin Simmel and the EFEU-team.- AFO2000 Newsletter 5 (12-2003) (English, Dec. 2003; 2.129 KB)	- 4 pages

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Last change: 24/06/2004