Role of external factors in the evolution of the ozone layer and stratospheric circulation in 21st century

• Main Authors: Zubov, V., Rozanov, Eugene, Egorova, Tatiana, Karol, I., Schmutz, Werner
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus 2012
• Subjects: Sea ice
• Online Access: https://hdl.handle.net/20.500.11850/61846; https://doi.org/10.3929/ethz-b-000061846

The chemistry-climate model (CCM) SOCOL has been used to evaluate the contribu-tion of the main anthropogenic factors to the simulated changes of ozone and strato-spheric dynamics during the 21st century. As the main anthropogenic factors we con-sider atmospheric concentration of the greenhouse gases (GHG), ozone depleting substances (ODS) and sea surface temperature and sea ice (SST/SI) distribution. The lastone is considered here as an independent factor because the majority of the CCMsprescribe its evolution. We have performed three sets of “time-slice” numerical exper-iments with CCM SOCOL for the years 2000, 2050, and 2100 taking into account allfactors separately and all together. It was established that the total column ozone increase during the first half of the 21st century is caused by the ODS, especially in themiddle and high latitudes of both hemispheres. In the tropics and the extra tropical re-gion of the Northern Hemisphere (NH) the SST/SI forcing plays very important role inthe evolution of ozone atmospheric content during the second half of the 21st century.The GHG affect the temperature and ozone mainly in the upper stratosphere and in thelower stratosphere of the high latitudes of the Southern Hemisphere (SH). In the lowertropical stratosphere of the NH the long-term changes of the temperature, zonal windvelocity and the meridional circulation intensity are controlled mainly by the SST/SI.The strong contribution of the SST/SI to the ozone and circulation changes in the fu-ture implies that some differences between the simulated results could be caused by the applied SST/SI rather than by the CCM’s deficiencies. We suggest taking this issueinto account for the planning of the future model evaluation campaigns. ISSN:1680-7375 ISSN:1680-7367