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| Titel |
Quantifying transport into the Arctic lowermost stratosphere |
| VerfasserIn |
A. Werner, C. M. Volk, E. V. Ivanova, T. Wetter, C. Schiller, H. Schlager, P. Konopka |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 23 ; Nr. 10, no. 23 (2010-12-08), S.11623-11639 |
| Datensatznummer |
250008944
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| Publikation (Nr.) |
 copernicus.org/acp-10-11623-2010.pdf |
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| Zusammenfassung |
| In the Arctic winter 2003, in-situ measurements of the long-lived
trace gases N2O, CFC-11 (CCl3F), H-1211
(CBrClF2), CH4, O3 and H2O have been
performed on board the high-altitude aircraft M55 Geophysica. The
data are presented and used to study transport into the lowermost
stratosphere (LMS). The LMS can be regarded as a mixture of
fractions of air originating in (i) the troposphere, (ii) the
extra-vortex stratosphere above 400 K and (iii) the Arctic vortex
above 400 K. These fractions are determined using a
simple mass balance calculation. The analysis exhibits a strong
tropospheric influence of 50% ± 15% or more in the lowest
20 K of the high-latitude LMS. Above this region the
LMS is dominated by air masses having descended from above
400 K. Below the Arctic vortex region at potential
temperatures above 360 K, air in the LMS is a mixture
of extra-vortex stratospheric and vortex air masses. The vortex
fraction increases from about 40% ± 15% at 360 K to 100% at 400 K for
equivalent latitudes >70° N. This influence of air masses descending through the
bottom of the polar vortex increases over the course of the winter.
By the end of winter a significant fraction of 30% ± 10%
vortex air in the LMS is found even at an equivalent latitude of
40° N. Since the chemical and dynamical history of vortex air
is distinct from that of mid-latitude stratospheric air masses, this
study implies that the composition of the mid- to high-latitude LMS
during late winter and spring is significantly influenced by the
Arctic vortex. |
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