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| Titel |
Effects of asymmetric ozone changes in a coupled ocean-middle-atmosphere-model under present day conditions |
| VerfasserIn |
Ingo Kirchner, Axel Gabriel, Hans-F. Graf, Ines Hoeschel, Dieter H. W. Peters |
| 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 |
250055482
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| Zusammenfassung |
| In the middle and upper atmosphere the radiative forcing will be
controlled by the ozone. In coupeld climate models of IPCC only the
zonal symmetric part of the ozone distribution is implemented. In
contrast to this approximation the observed trends of ozone during the
1990's shows an increased planetary wave one pattern. The response of
such ozone anomalies is studied with the coupled ocean-atmosphere
model COSMOS.
The model resolution of the atmosphere part is T31 with 90 levels from
the surface to about 80 km height. The ocean model has a 3 degree
resolution with 40 levels. After a spinup phase of 200 years three
simulations were launched. In addition to the 80 year reference
experiments two sensitivity experiments were performed. In both the
asymmetric part of the observed ozone during the 1990's is added to
the model background ozone northward of 30°N. In the first experiment
(S1) the ozone is modified between 500 and 2 hPa and in the second
experiment (S2) from 10 to 2 hPa in order to differentiate between
whole and only upper stratospheric ozone forcing.
The model responds in both sensitivity experiments with a planetary
wave two signal in the upper stratosphere and lower mesosphaere. The
significant systematic changes in the troposphere are stronger in the
experiment with forcing in the upper stratosphere only (S2). In both
experiments the Island low is weakend and the North Pacific low is
intensified during northern winter. |
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