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Wolff, Veronika ; Trebs, Ivonne ; Ammann, Christof ; Meixner, Franz X.:
Aerodynamic gradient measurements of the NH3–HNO3–NH4NO3 triad using a wet chemical instrument : an analysis of precision requirements and flux errors.
In: Atmospheric Measurement Techniques Discussions.
Bd. 2
(2009)
.
- S. 2423-2482.
ISSN 1867-8610
DOI: https://doi.org/10.5194/amtd-2-2423-2009
Abstract
The aerodynamic gradient method is widely used for flux measurements of ammonia, nitric acid, particulate ammonium nitrate (the NH3-HNO3-NH4NO3 triad) and otherwater-soluble reactive trace compounds. The surface exchange flux is derived from a measured concentration difference and micrometeorological quantities (turbulent exchange coefficient). The significance of the measured concentration difference is crucialfor the significant determination of surface exchange fluxes. Additionally, measurementsof surface exchange fluxes of ammonia, nitric acid and ammonium nitrate are often strongly affected by phase changes between gaseous and particulate compounds of the triad, which make measurements of the four individual species (NH3, HNO3, NH+4 , NO−3 ) necessary for a correct interpretation of the measured concentrationdifferences. We present here a rigorous analysis of results obtained with a multi-component, wetchemical instrument, able to simultaneously measure gradients of both gaseous and particulate trace substances. Basis for our analysis are two field experiments, conductedabove contrasting ecosystems (grassland, forest). Precision requirements of the instrument as well as errors of concentration differences and micrometeorologicalexchange parameters have been estimated, which, in turn, allows the establishment of thorough error estimates of the derived fluxes of NH3, HNO3, NH+4 , and NO−3 . Derived median flux errors for the grassland and forest field experiments were: 39 and 50%(NH3), 31 and 38% (HNO3), 62 and 57% (NH+4 ), and 47 and 68% (NO−3 ), respectively. Additionally, we provide the basis for using field data to characterize the instrument performance, as well as subsequent quantification of surface exchange fluxes and underlying mechanistic processes under realistic ambient measurement conditions.
Weitere Angaben
| Publikationsform: | Artikel in einer Zeitschrift |
|---|---|
| Begutachteter Beitrag: | Ja |
| Zusätzliche Informationen: | BAYCEER78705 |
| Institutionen der Universität: | Forschungseinrichtungen > Zentrale wissenschaftliche Einrichtungen > Bayreuther Zentrum für Ökologie und Umweltforschung - BayCEER Forschungseinrichtungen Forschungseinrichtungen > Zentrale wissenschaftliche Einrichtungen |
| Titel an der UBT entstanden: | Ja |
| Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik |
| Eingestellt am: | 07 Aug 2015 06:59 |
| Letzte Änderung: | 08 Nov 2023 10:57 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/17747 |