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| Titel |
Recent Advances in Detection of Ammonia and Nitric Acid on Short Timescales Suitable for Eddy Covariance Flux Measurements |
| VerfasserIn |
Joseph Roscioli, Scott Herndon, Mark Zahniser, David Nelson, Barry McManus |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250107624
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| Publikation (Nr.) |
 EGU/EGU2015-7332.pdf |
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| Zusammenfassung |
| Ammonia and nitric acid play important roles in aerosol, cloud, and NOx chemistry.
Accurately measuring these species’ concentrations on a fast timescale has historically been
complicated due to their tendency to slowly and irreversibly interact with instrument surfaces.
Here we present recent efforts aimed at mitigating these effects using new inlet
technologies. First, an inlet that combines an inertial impactor with a pressure drop
across a critical orifice provides particle removal without a traditional filter. This
approach is used to reduce instrumental time responses for NH3 and HNO3 to 3-15
seconds. Second, a further reduction in time response is achieved by entraining
functionalized perfluoroalkane vapor into the inlet sampling stream. This "active
passivation" method is used to achieve time responses of ~0.5 seconds for both NH3 and
HNO3, and is found to be applicable to a variety of inlet designs. These technologies
enable fast time response sampling suitable for eddy covariance flux measurements. |
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