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| Titel |
Vertical structure of Antarctic tropospheric ozone depletion events: characteristics and broader implications |
| VerfasserIn |
A. E. Jones, P. S. Anderson, E. W. Wolff, H. K. Roscoe, G. J. Marshall, A. Richter, N. Brough, S. R. Colwell |
| 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. 16 ; Nr. 10, no. 16 (2010-08-24), S.7775-7794 |
| Datensatznummer |
250008720
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| Publikation (Nr.) |
 copernicus.org/acp-10-7775-2010.pdf |
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| Zusammenfassung |
| The majority of tropospheric ozone depletion event (ODE) studies have
focussed on time-series measurements, with comparatively few studies of the
vertical component. Those that exist have almost exclusively used
free-flying balloon-borne ozonesondes and almost all have been conducted in
the Arctic. Here we use measurements from two separate Antarctic field
experiments to examine the vertical profile of ozone during Antarctic ODEs.
We use tethersonde data to probe details in the lowest few hundred meters
and find considerable structure in the profiles associated with complex
atmospheric layering. The profiles were all measured at wind speeds less
than 7 ms−1, and on each occasion the lowest inversion height lay
between 10 m and 40 m. We also use data from a free-flying ozonesonde study
to select events where ozone depletion was recorded at altitudes >1 km
above ground level. Using ERA-40 meteorological charts, we find that on
every occasion the high altitude depletion was preceded by an atmospheric
low pressure system. An examination of limited published ozonesonde data
from other Antarctic stations shows this to be a consistent feature. Given
the link between BrO and ODEs, we also examine ground-based and satellite
BrO measurements and find a strong association between atmospheric low
pressure systems and enhanced BrO that must arise in the troposphere. The
results suggest that, in Antarctica, such depressions are responsible for
driving high altitude ODEs and for generating the large-scale BrO clouds
observed from satellites. In the Arctic, the prevailing meteorology differs
from that in Antarctica, but, while a less common effect, major low pressure
systems in the Arctic can also generate BrO clouds. Such depressions thus
appear to be fundamental when considering the broader influence of ODEs,
certainly in Antarctica, such as halogen export and the radiative influence
of ozone-depleted air masses. |
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