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| Titel |
Acetaldehyde exchange above a managed temperate mountain grassland |
| VerfasserIn |
L. Hörtnagl, I. Bamberger, M. Graus, T. M. Ruuskanen, R. Schnitzhofer, M. Walser, A. Unterberger, A. Hansel, G. Wohlfahrt |
| 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 ; 14, no. 11 ; Nr. 14, no. 11 (2014-06-03), S.5369-5391 |
| Datensatznummer |
250118764
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| Publikation (Nr.) |
 copernicus.org/acp-14-5369-2014.pdf |
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| Zusammenfassung |
An overview of acetaldehyde exchange above a managed temperate mountain
grassland in Austria over four growing seasons is presented. The meadow
acted as a net source of acetaldehyde in all 4 years, emitting between 7
and 28 mg C m−2 over the whole growing period. The cutting of the
meadow resulted in huge acetaldehyde emission bursts of up to
16.5 nmol m−2 s−1 on the day of harvesting or 1 day later. During
undisturbed conditions both periods with net uptake and net emissions of
acetaldehyde were observed. The bidirectional nature of acetaldehyde fluxes
was also reflected by clear diurnal cycles during certain time periods,
indicating strong deposition processes before the first cut and emission
towards the end of the growing season.
The analysis of acetaldehyde compensation points revealed a complex
relationship between ambient acetaldehyde mixing ratios and respective
fluxes, significantly influenced by multiple environmental parameters and
variable throughout the year. As a major finding of this study, we
identified both a positive and negative correlation between concentration
and flux on a daily scale, where soil temperature and soil water content
were the most significant factors in determining the direction of the slope.
In turn, this bidirectional relationship on a daily scale resulted in
compensation points between 0.40 and 0.54 ppbv, which could be well
explained by collected ancillary data. We conclude that in order to model
acetaldehyde fluxes at the site in Neustift on a daily scale over longer
time periods, it is crucial to know the type of relationship, i.e., the
direction of the slope, between mixing ratios and fluxes on a given day. |
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