Stratosphere—troposhere exchange of ozone at Indian Antarctic station, Maitri

The frequency of occurrence of stratosphere–tropo-sphere exchange (STE) events and the depth up to which ozone from the stratosphere descended into the troposphere during these events has been examined at the Indian Antarctic research station, Maitri. It is concluded that STE plays a minor role in the tropo-spheric ozone budget. Stratospheric intrusions at Maitri were associated with pronounced cut-off circu-lations, which provided a large reservoir of ozone-rich air for eventual transport to the lower troposphere. However, these intrusions rarely reached the earth's surface.