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| Titel |
Observations and methodology of atmospheric ammonia within the Colorado
Rocky Mountain pine forest |
| VerfasserIn |
Amy Hrdina, Alexander Moravek, Jennifer Murphy |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250129914
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| Publikation (Nr.) |
 EGU/EGU2016-10087.pdf |
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| Zusammenfassung |
| Concentrations of trace gases (HCl, HNO3, HONO, NH3, SO2) and particle phase
constituents from fine particulate matter (PM2.5) were continuously measured using an online
ambient ion monitor ion chromatograph (AIM-IC) within the canopy at the Rocky Mountain
Research Station (Manitou Experimental Forest) in Woodland Park, Colorado, from July 31 –
August 12 2015. A consistent diurnal pattern of ammonia mixing ratios was observed,
ranging from 0.1 – 2.6 ppb. Analysis of PM2.5ammonium was below the 130 ng m−3
detection limit of the instrument, which was corroborated by parallel particle concentration
data also gathered at the site showing extremely low overall particle concentrations in the
order of 103. As a result, variability in gas phase ammonia can be attributed to
surface-atmosphere exchange and/or transport rather than gas particle partitioning.
Complimentary analysis of ammonium found within the pine needles and the soil was also
performed on site using established extraction methods and analysis by ion chromatography.
Emissions potentials calculated from observed ammonium levels were generally consistent in
the pine needles showing stomatal emission potentials within the range of 28 – 60, whereas
the soil data varied widely, spanning 5 – 2100. The measurements are used to quantify
compensation points of ammonia representative of the canopy and ground at the site to
better predict the biosphere-atmosphere exchange of ammonia within the forest. |
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