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| Titel |
Development of a model to simulate the impact of atmospheric stability on N2O-fluxes from soil |
| VerfasserIn |
Christoph Thieme, Christian Klein, Christian Biernath, Florian Heinlein, Eckart Priesack |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250095912
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| Publikation (Nr.) |
 EGU/EGU2014-11387.pdf |
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| Zusammenfassung |
| The trace gas N2O, mainly produced by microorganisms in agricultural soils, is a very
stable and thus potent greenhouse gas and is the main contributor for the recent
depletion of ozone in the stratosphere. Therefore N2O-emissions need to be mitigated
and thus much effort has been made to reveal the causes of N2O-formation in
soils. At present some crucial drivers for N2O-fluxes are known, but underlying
processes of N2O-fluxes are not yet understood or described adequately. An important
shortcoming is the description of the upper boundary layer at the soil-atmosphere
interface.
Therefore, the aim of this study is to develop a mechanistic simulation model, which
considers both the formation of N2O in agricultural soils, and the impact of the atmospheric
conditions on the transport of soil-born N2O into the atmosphere. The new model simulates
N2O-flux as a function of meteorological values instead of a model that just releases the
whole amount of N2O into the atmosphere.
For this purpose the modular ecosystem model framework Expert-N, which allows to
simulate the formation of N2O in the soils will be extended to a model with a more detailed
description of the upper boundary condition at the soil-atmosphere interface. In detail, this is
realized in the form of a resistance approach, where N2O-fluxes are constrained by a land-air
resistance that depends on a Bulk-Exchange Coefficient, wind speed and a gradient of N2O
concentrations in the lower atmosphere. Descriptions of atmospheric stability follow the
Monin-Obhukov Similarity Theory.
The newly developed model will be validated using Eddy Covariance measurements of
N2O-fluxes. Measurement device for the N2O concentrations is a Quantum-Cascade-Dual-Laser
produced by Aerodyne Research Inc. (Billerca, Mass., USA). The measurements were
conducted on an intensively managed field at the TERENO research farm Scheyern
(Germany), which is part of the TERENO Bavarian Alps / Pre-Alps observatory. |
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