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| Titel |
Attribution of stratospheric ozone trends to chemistry and transport: a modelling study |
| VerfasserIn |
G. Kiesewetter, B.-M. Sinnhuber, M. Weber, J. P. Burrows |
| 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. 24 ; Nr. 10, no. 24 (2010-12-17), S.12073-12089 |
| Datensatznummer |
250008970
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| Publikation (Nr.) |
 copernicus.org/acp-10-12073-2010.pdf |
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| Zusammenfassung |
| The decrease of the concentration of ozone depleting substances
(ODSs) in the stratosphere over the past decade raises the
question to what extent observed changes in stratospheric ozone
over this period are consistent with known changes in the
chemical composition and possible changes in atmospheric
transport. Here we present a series of ozone sensitivity
calculations with a stratospheric chemistry transport model (CTM)
driven by meteorological reanalyses from the European Centre for
Medium-Range Weather Forecasts, covering the period 1978–2009.
In order to account for the reversal in ODS trends, ozone trends
are analysed as piecewise linear trends over two periods,
1979–1999 and 2000–2009. Modelled column ozone (TO3)
inter-annual variability and trends are in excellent agreement
with observations from the Total Ozone Mapping Spectrometer
(TOMS) and Solar Backscatter UV (SBUV/2) as well as the Global
Ozone Monitoring Experiment (GOME/GOME2) and Scanning Imaging
Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY)
instruments. In the period 1979–1999, modelled TO3 trends at
mid-latitudes are dominated by changes in in situ gas-phase
chemistry, which contribute to about 50% or more of the TO3 trend
in most seasons. Changes in meteorology contribute around 35% to
mid-latitude TO3 trends, with strong differences between
different seasons. In springtime, export of ozone depleted air
from polar latitudes contributes about 35–50% to the modelled
TO3 trend at SH mid-latitudes and about 15–30% at NH
mid-latitudes. Over the period 2000–2009 positive linear trends
in modelled TO3, which agree well with observed TO3 trends, are
dominated by changes in meteorology, as expected for the yet
small decrease in stratospheric halogen loading over this period.
While the TO3 trends themselves are not statistically significant
over the period 2000–2009, changes in linear trends between
1978–1999 and 2000–2009 are significant at mid- and high
latitudes of both hemisphere during most seasons. However,
changes in meteorology have contributed substantially to these
TO3 trend changes. |
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