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| Titel |
Variability in Antarctic ozone loss in the last decade (2004–2013): high-resolution simulations compared to Aura MLS observations |
| VerfasserIn |
J. Kuttippurath, S. Godin-Beekmann, F. Lefèvre, M. L. Santee, L. Froidevaux, A. Hauchecorne |
| 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 ; 15, no. 18 ; Nr. 15, no. 18 (2015-09-22), S.10385-10397 |
| Datensatznummer |
250120042
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| Publikation (Nr.) |
 copernicus.org/acp-15-10385-2015.pdf |
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| Zusammenfassung |
| A detailed analysis of the polar ozone loss processes during 10 recent
Antarctic winters is presented with high-resolution MIMOSA–CHIM (Modèle
Isentrope du transport Méso-échelle de l'Ozone Stratosphérique
par Advection avec CHIMie) model
simulations and high-frequency
polar vortex observations from the Aura microwave limb sounder (MLS)
instrument. The high-frequency measurements and simulations help to
characterize the winters and assist the interpretation of interannual
variability better than either data or simulations alone. Our model results
for the Antarctic winters of 2004–2013 show that chemical ozone loss starts
in the edge region of the vortex at equivalent latitudes (EqLs) of
65–67° S in mid-June–July. The loss progresses with time at
higher EqLs and intensifies during August–September over the range
400–600 K. The loss peaks in late September–early October, when all
EqLs (65–83° S) show a similar loss and the maximum loss (>
2 ppmv – parts per million by volume) is found over a broad
vertical range of 475–550 K. In the lower stratosphere, most winters
show similar ozone loss and production rates. In general, at 500 K,
the loss rates are about 2–3 ppbv sh−1 (parts per billion by volume
per sunlit hour) in July and 4–5 ppbv sh−1 in August–mid-September,
while they drop rapidly to 0 by mid-October. In the middle
stratosphere, the loss rates are about 3–5 ppbv sh−1 in July–August
and October at 675 K. On average, the MIMOSA–CHIM simulations show
that the very cold winters of 2005 and 2006 exhibit a maximum loss of
~ 3.5 ppmv around 550 K or about 149–173 DU over
350–850 K, and the warmer winters of 2004, 2010, and 2012 show a
loss of ~ 2.6 ppmv around 475–500 K or
131–154 DU over 350–850 K. The winters of 2007, 2008, and
2011 were moderately cold, and thus both ozone loss and peak loss altitudes
are between these two ranges (3 ppmv around 500 K or
150 ± 10 DU). The modeled ozone loss values are in reasonably good
agreement with those estimated from Aura MLS measurements, but the model
underestimates the observed ClO, largely due to the slower vertical descent
in the model during spring. |
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