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| Titel |
Global distribution of halogenated tracers in the UTLS region during the TACTS/ESMVal campaigns using the HALO aircraft |
| VerfasserIn |
Timo Keber, Andreas Engel, Harald Boenisch, Stephan Sala |
| 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 |
250073689
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| Zusammenfassung |
| The Upper Troposphere / Lower Stratosphere (UTLS) represents an important region for the
exchange of air between the stratosphere and the troposphere. Tropospheric gaseous
compounds such as greenhouse gases and ozone depleting substances (ODS) are transported
into the lower stratosphere on different pathways. Especially the two-way horizontal transport
across the subtropical jet was further investigated during the “TACTS – Transport and
Composition in the UT/LMS” campaign.
We will present in-situ measurements of long-lived and very short-lived (VSLS)
halocarbons and Sulfurhexafluoride (SF6) in the UTLS region. The measurements were
performed with a sophisticated two channel in-situ instrument on board of the new
German research aircraft for atmospheric science HALO (The High Altitude and
LOng Range Research Aircraft) during the two campaigns TACTS and “ESMVal –
Earth System Modell Validation”. The first channel is a gas chromatography (GC)
system coupled with mass spectrometer (MS) which operates in negative chemical
ionization mode. This GC/MS channel is able to measure halocarbons in ambient air
with a time resolution of four minutes. For the measurement of SF6 and CFC-12
the second channel provides its own GC system with an electron capture detector
(ECD). With the GC/ECD we achieve a time resolution of 60 seconds. The dataset
includes 13 flights with a total of 120 flight hours and a coverage from 80Ë N to
65Ë S with a maximum altitude of 15 km. The measurements include halogenated
hydrocarbons with a wide span of chemical lifetimes reaching from 100 years for
CFC-12 to 26 days for CHBr3. On the basis of this distribution we can improve our
understanding of transport timescales, compositions and pathways in the UTLS region.
Furthermore we discuss the distribution in respect of atmospheric transport and lifetimes. |
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