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| Titel |
Interannual and seasonal variability of CH4 and N2O exchange over a temperate mountain grassland |
| VerfasserIn |
L. Hörtnagl, G. Wohlfahrt |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250065913
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| Zusammenfassung |
| Methane (CH4) and nitrous oxide (N2O) are major greenhouse gases and therefore play an
important role in the atmosphere due to their warming potential. The various processes and
mechanisms associated with the release and uptake of both compounds need further
investigation to reliably assess CH4 and N2O budgets in different ecosystems.
The exchange of CO2, CH4 and N2O was measured over 2 years at a temperate mountain
grassland managed as a hay meadow near the village Neustift in the Stubai Valley, Austria.
The three wind components, the speed of sound and the CO2mole densities were
acquired at a time resolution of 20 Hz and used to calculate true eddy covariance
CO2fluxes. CH4and N2O concentration values were recorded at 2 Hz, resulting
in a disjunct time series when compared to the 20 Hz wind data. Fluxes of both
compounds were then calculated using the virtual disjunct eddy covariance method
(vDEC).
The net ecosystem exchange of CO2 is monitored since 2001, while the measurement of
CH4 and N2O fluxes started in April 2010. During the vegetation period, typical
concentration values for CH4 and N2O were around 2.0 and 0.3 ppm, respectively, with both
compounds exhibiting distinct diurnal cycles. Preliminary flux calculations showed minor,
close-to-zero fluxes for both CH4 and N2O associated with large uncertainties owing to a
number of corrections that need to be applied during post-processing.
In this presentation we present final fluxes over two vegetation periods and investigate
drivers on observed CH4and N2O emission patterns. The role of management events like
harvesting of the vegetation and the spreading of manure will be investigated in detail and set
in relation to previously published studies. |
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