 |
| Titel |
21st Century Trends in the Potential for Ozone Depletion |
| VerfasserIn |
M. M. Hurwitz, P. A. Newman |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250019400
|
|
|
|
|
|
| Zusammenfassung |
| Previous work has suggested that, in the coming century, stratospheric temperatures will decrease due to greenhouse gas-related climate change. We find statistically significant trends in the area where Antarctic stratospheric temperatures are below 195K, the threshold for polar stratospheric cloud (PSC) formation, in Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) simulations of the first half of the 21st century. In late winter (September-October-November), the cold area trends are consistent with the respective trends in equivalent effective stratospheric chlorine (EESC) in each simulation (i.e. negative cold area trends in ‘realistic future’ simulations where EESC decreases and the ozone layer recovers). In the early winter (April-May-June), regardless of EESC scenario, we find an increasing cold area trend in all transient simulations of the 2000-2050 period; multiple linear regression analysis shows that this early winter cooling trend is associated with the predicted increase in greenhouse gas concentrations in future.
We compare the seasonality of the potential for Antarctic ozone depletion in two versions of the GEOS CCM, note the similarly between trends calculated with zonally-varying versus zonal mean temperature fields, and assess the impact of the above-mentioned cold area trends on polar stratospheric chemistry. |
|
|
|
|
|
|