Evolution of the Antarctic Spring Ozone Anomaly: Observation Results

The properties and peculiarities of the Antarctic spring ozone anomaly are described, making it possible to compare anomalies occurring in different years, and the possibility of the occurrence of this phenomenon in the Northern Hemisphere is discussed. It is shown that the principal indicator of the phenomenon is an anomaly in the seasonal variation of total ozone content (TOC). During the spring, when a TOC maximum should be observed in the "normal" seasonal variation, its considerable decrease occurs annually over a prolonged time (more than a month). The anomaly in the year 2000 especially graphically revealed a definite role of meteorological conditions in the appearance and development of the anomaly. It is demonstrated that in the majority of latitudinal zones a TOC minimum was observed that had begun about 1990 in the equatorial region and gradually propagated poleward. Over the greater part of the globe, the TOC minimum was observed earlier than the maximum stratospheric concentration of chlorofluorocarbons.