Abstract

The catalytic destruction of ozone by components of the odd nitrogen (NO_y), odd chlorine (CℓO_y), and odd hydrogen (HO_y) chemical families of the middle atmosphere has been a concern for many years. Key components of NO_y were observed by experiments on the Nimbus 7, SAGE, and SME satellites. These data provided answers to a number of important scientific questions, but they also raised other issues which remain unanswered today. Middle atmosphere research has been further sharpened by the discovery of the springtime Antarctic ozone hole. This phenomenon 1s believed to occur because of chlorine catalyzed ozone destruction aided by heterogenous chemistry processes which are enhanced in the polar regions by the presence of polar stratospheric clouds (Solomon, 1988). Much higher levels of active chlorine are observed 1n the Antarctic winter - spring period (Solomon et al., 1987) than at lower latitudes, and consistent with this, the HCℓ to HF ratio is smaller. The Upper Atmosphere Research Satellite (UARS) complement of measurements has been designed to provide further and more comprehensive NO_y and CℓO_y observations over a long time period in order to address the outstanding scientific issues.

© 1990 Optical Society of America