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| Titel |
Measurements of Volatile Organic Compounds (VOCs) on Board of the Zeppelin NT during the PEGASOS Campaign in 2012 |
| VerfasserIn |
Julia Jäger, Andreas Hofzumahaus, Harry Beck, Franz Rohrer, Sebastian Broch, Hendrik Fuchs, Sebastian Gomm, Frank Holland, Keding Lu, Astrid Kiendler-Scharr, Thomas Mentel, Bernhard Rose, Robert Wegener, Andreas Wahner |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250076568
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| Zusammenfassung |
| Volatile Organic Compounds (VOCs) are mostly emitted at the ground and are degraded by
the reactions with OH, NO3 or O3 as they rise upwards in the atmosphere. VOCs play an
important role as sources and sinks for radicals in the troposphere. Up to date, most of
the VOC measurements were performed from ground based platforms; the profile
measurements across the whole planetary boundary layer (PBL) are still quite limited which
restrained the exploring of the VOCs chemistry of the entire PBL. This although these
measurements are particularly interesting, as most of the chemistry of the VOC degradation
in the troposphere takes place in the PBL. Moreover, fast VOCs measurements
utilizing Gas Chromatography coupled with Mass Spectrometry (GC-MS) are a
challenge due to the great chemical variability of VOC species. Therefore accurate
in-situ measurements of VOCs together with other species as CO, NOx, O3 and the
OH reactivity, encompassing different levels of altitude and fast time resolution,
would essentially improve the understanding of the VOC distribution in the lower
troposphere.
Here we present the setup and the modifications of the fast GC-MS system and the results
of the PEGASOS Zeppelin campaigns in summer 2012. First, we present our developments
and modifications of an in-flight GC-MS system to detect volatile non methane hydrocarbons
(NMHC) with a time resolution of 3 minutes and a detection limit in the order of 2 pptv. The
modified setup enabled us to analyze 70 different VOC species, ranging from alkanes (C4 to
C11), aromatics and terpenes to oxygenated hydrocarbons (OVOC) such as alcohols and
aldehydes.
Second, in contrast to previous airplane studies also utilizing a GC-MS system, the
Zeppelin NT as a measuring platform during the PEGASOS campaign enabled us to measure
vertical profiles up to 1500m at low travelling speeds which means a high spatial resolution.
We will present results for selected VOC that offer new insights on height profiles
encompassing different emission regimes (anthropogenic and biogenic) in both
the Netherlands and in Italy, and on the fate of VOCs in the nocturnal boundary
layer.
Third, we also present how the VOC concentrations relate to other substances
such as CO, NOx, O3 and the OH reactivity. Especially the comparison of VOC
Data with the measured OH reactivity will reveal more insight into the ’missing
reactivity’.
Acknowledgement: PEGASOS project funded by the European Commission under the
Framework Program 7 (FP7-ENV-2010-265148) |
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