 |
| Titel |
Ozone Depletion, Increasing Greenhouse Gases, and Southern Hemisphere Climate Change |
| VerfasserIn |
L. M. Polvani, D. W. Waugh, G. Correa, S. W. Son |
| Konferenz |
EGU General Assembly 2010
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250039968
|
|
|
|
|
|
| Zusammenfassung |
| Analyses of integrations with IPPC/AR4 ocean-atmosphere coupled models,
and with stratosphere-resolving chemistry-coupled models from the
SPARC/CCMVal inter comparison project, suggest that ozone depletion is
capable of producing a considerable impact on the tropospheric
circulation of the entire Southern Hemisphere, notably on the poleward
shift of the midlatitude jet and the widening of the Hadley cell during
austral summer. However, integrations without ozone depletion show that
increasing greenhouse gases are also responsible for the such shifts.
Hence the relative roles of ozone depletion and greenhouse gas increase
remain unclear. Part of the difficulty in assesing the relative
importance of these two forcings is the large interannual variability,
which is comparable in magnitude to the response to ozone and greenhouse
forcings in the recent past. To address this limitation, we have
performed a new set of long, time-slice integrations with NCAR's
atmospheric model (CAM) in which ozone depletion and increased green
house gases are specified independently. Analysis of this new set of
integrations reveals that, for the Southern Hemisphere summer in the
second half of the 20th century, only ozone depletion is able to produce
statistically significant climate shifts in the model. This suggests
that ozone depletion may in fact have been the dominant driver of
climate change in the Southern Hemisphere in the last half century. |
|
|
|
|
|
|