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| Titel |
Abiotic and biotic control of methanol exchanges in a temperate mixed forest |
| VerfasserIn |
Q. Laffineur, M. Aubinet, N. Schoon, C. Amelynck, J.-F. Müller, J. Dewulf, H. Langenhove, K. Steppe, B. Heinesch |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 1 ; Nr. 12, no. 1 (2012-01-11), S.577-590 |
| Datensatznummer |
250010452
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| Publikation (Nr.) |
 copernicus.org/acp-12-577-2012.pdf |
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| Zusammenfassung |
Methanol exchanges over a mixed temperate forest in the Belgian Ardennes
were measured for more than one vegetation season using disjunct
eddy-covariance by a mass scanning technique and Proton Transfer Reaction
Mass Spectrometry (PTR-MS). Half-hourly methanol fluxes were measured in the
range of −0.6 μg m−2 s−1 to 0.6 μg m−2 s−1,
and net daily methanol fluxes were generally negative in summer and autumn
and positive in spring. On average, the negative fluxes dominated (i.e. the
site behaved as a net sink), in contrast to what had been found in previous
studies.
An original model describing the adsorption/desorption of methanol in water
films present in the forest ecosystem and the methanol degradation process
was developed. Its calibration, based on field measurements, predicted a
mean methanol degradation rate of −0.0074 μg m−2 s−1 and a
half lifetime for methanol in water films of 57.4 h. Biogenic emissions
dominated the exchange only in spring, with a standard emission factor of
0.76 μg m−2 s−1.
The great ability of the model to reproduce the long-term evolution, as well
as the diurnal variation of the fluxes, suggests that the
adsorption/desorption and degradation processes play an important role in
the global methanol budget. This result underlines the need to conduct
long-term measurements in order to accurately capture these processes and to
better estimate methanol fluxes at the ecosystem scale. |
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