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| Titel |
Comparison of methods for the determination of NO-O3-NO2 fluxes and chemical interactions over a bare soil |
| VerfasserIn |
P. Stella, B. Loubet, P. Laville, E. Lamaud, M. Cazaunau, S. Laufs, F. Bernard, B. Grosselin, N. Mascher, R. Kurtenbach, A. Mellouki, J. Kleffmann, P. Cellier |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 5, no. 6 ; Nr. 5, no. 6 (2012-06-01), S.1241-1257 |
| Datensatznummer |
250002963
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| Publikation (Nr.) |
 copernicus.org/amt-5-1241-2012.pdf |
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| Zusammenfassung |
| Tropospheric ozone (O3) is a known greenhouse gas responsible for
impacts on human and animal health and ecosystem functioning. In addition,
O3 plays an important role in tropospheric chemistry, together with
nitrogen oxides. The determination of surface-atmosphere exchange fluxes of
these trace gases is a prerequisite to establish their atmospheric budget
and evaluate their impact onto the biosphere. In this study, O3, nitric
oxide (NO) and nitrogen dioxide (NO2) fluxes were measured using the
aerodynamic gradient method over a bare soil in an agricultural field. Ozone
and NO fluxes were also measured using eddy-covariance and automatic
chambers, respectively. The aerodynamic gradient measurement system, composed
of fast response sensors, was capable to measure significant differences in
NO and O3 mixing ratios between heights. However, due to local
advection, NO2 mixing ratios were highly non-stationary and NO2
fluxes were, therefore, not significantly different from zero. The chemical
reactions between O3, NO and NO2 led to little ozone flux
divergence between the surface and the measurement height (less than 1%
of the flux on average), whereas the NO flux divergence was about 10% on
average. The use of fast response sensors allowed reducing the flux
uncertainty. The aerodynamic gradient and the eddy-covariance methods gave
comparable O3 fluxes. The chamber NO fluxes were down to 70% lower
than the aerodynamic gradient fluxes, probably because of either the spatial
heterogeneity of the soil NO emissions or the perturbation due to the
chamber itself. |
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