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Emission and Chemical Transformation of Biogenic Volatile Organic Compounds
ECHOFrom 01/2002 to 03/2004
Staff: Jens-Christopher Mayer, Christoph Thomas, Michael Kortner
Forests are complex sources of biogenic volatile organic compounds (VOC) in the
planetary boundary layer. Previous studies estimate that global emissions of
biogenic VOC are in the range of 490 Tg C/year to 1150 Tg C/year and thus a
factor of 5 to 10 higher than anthropogenic emissions. Therefore, biogenic VOC
contribute significantly to the formation of photo-oxidants in the troposphere. Due to
fast vertical transport processes, they may even have an impact on the chemistry of
the upper troposphere. Recent airborne measurements show surprisingly high
mixing ratios of reactive compounds such as acetone, formaldehyde, methanol,
hydrogen peroxide and organic hydroperoxides. These compounds are believed to
originate from primary biogenic emissions or to be oxidation products of biogenic
VOC.
All together, the impact of biogenic VOC on tropospheric photochemistry, air
quality, and the formation of secondary products affecting our climate on a regional
and global scale are far from being understood. A considerable lack of knowledge
exists concerning a typical forest stand as a net source of reactive trace
compounds, the amount of primary emitted VOC which are transported directly into
the PBL, and the amount of VOC which are chemically processed within the
canopy, the products of which are transported into the PBL. The gas phase
chemistry above the canopy which is driven by high concentrations of reactive
precursor compounds and high UV radiation is also not yet understood. The goal of
the proposed project is to investigate these questions to improve our
understanding of biosphere-atmosphere interactions and effects on the planetary
boundary layer.
Homepage: http://www.fz-juelich.de/icg/icg-ii/echo
List of publications of this Project
Thomas, C; Mayer, JC; Meixner, FX; Foken, T: Analysis of the low-frequency turbulence above tall vegetation using a Doppler sodar, Boundary-Layer Meteorology, 119, 563-587 (2006), doi:10.1007/s10546-005-9038-0 -- Details |
Koppmann, R; Kesselmeier, J; Meixner, FX; Schatzmann, M; Leitl, B; Hoffmann, T; Dlugi, R; Zelger, M; Neftel, A; Dommen, J; Thomas, C; Neininger, B: Emission and chemical transformation of biogenic volatile organic compounds (ECHO) – Investigations in and above a mixed forest stand, Results of the German Atmospheric Research Programme - AFO 2000, 29-39 (2005) |
Related links:- Diploma Thesis: Characterisation of the Atmospheric Boundary-Layer in a Complex Terrain using SODAR-RASS
- Experiment: ECHO: ECHO Field Campains in 2002 and 2003
- PhD Thesis: Detection and analysis of coherent structures within and above tall-vegetated canopies
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