Session 4INV - Invited Session.
INVITED session, Tuesday, November 25
304-6, Moscone Center
Significant changes in the abundances of stratospheric ozone were first observed in the Antarctic but now extend over much of the globe. Measurements have established that chlorine chemistry due to human releases of chlorofluorocarbons is responsible for the annual ozone decrease popularly known as the "ozone hole". Significant ozone changes have also been observed in the Arctic and at mid-latitudes. Measurements of ozone changes throughout the world will be discussed, observations of related chemicals will be presented, and the current state of knowledge of present and future ozone depletion will be summarized. New research results relating to the causes of mid-latitude ozone depletion will also be presented, and projections of when the Antarctic ozone hole may 'close' will be described.