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| Titel |
CARIBIC passenger aircraft (2005-2010): What we have learnt so far from the trace gas distributions in the UTLS |
| VerfasserIn |
Andreas Zahn, Christoph Dyroff, Carl A. M. Brenninkmeijer, Tanja Schuck, Armin Raute-Schöch, Peter F. J. van Velthoven |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250056305
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| Zusammenfassung |
| As of May 2005 the CARIBIC passenger aircraft (Airbus A340-600 by Lufthansa) measures
regularly ~100 trace gases and aerosol parameters at 9-12 km altitude during four
long-distance flights per month. The measurements are done using a well-equipped flying
laboratory installed in the Airbus’ cargo bay. Flight destinations are from Germany to
North/South America, South-East Asia, and South Africa. Tropospheric and stratospheric air
is sampled with fractions of ~60% and ~40%, respectively. The stratospheric flight sections
largely occur in the extra-tropical tropopause (transition) layer (exTL). Besides the
observations, detailed meteorological information (including back-trajectories) along the
flight tracks is available.
One unrivalled power of CARIBIC is the interference of representative distributions and
seasonal variations of many trace gases in the upper troposphere and lower stratosphere
(UTLS). As the measured trace gases have different sources and sinks and thus different
atmospheric lifetimes and seasonal variations, their distributions reflect different atmospheric
processes and therefore can be utilized to better understand and quantify the controlling
processes. Here, examples of trace gas distributions collected since the year 2005 are
presented and discussed, e.g. of the long-lived greenhouse gases CO2, CH4, N2O, and
SF6 and of the more variable trace gases H2O and acetone. Distributions relative
to the tropopause are for instance interpreted to conclude on the transport and its
seasonal variation of tropospheric air into the lowermost stratosphere. In spring
the trace gas gradients across the tropopause are particularly strong, in autumn
however, the gradients minimize so that the chemical tropopause almost vanishes. |
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