Summary
The 2017 ozone hole developed in the first week of August and rose sharply to reach a peak size in early September, this was then followed by a significant warming event which reduced the overall areal extent of the ozone hole considerably. If this peak area in early September turns out to be the maximum for 2017, then the 2017 ozone hole will be one of the smallest recorded for many years and similar in size to the ozone holes observed in the mid- to late-1980s. During the presentation and update to this will be given which will incorporate the latest data available. The development and recovery of the 2017 ozone hole will be shown via a set of metrics based on the Ozone Monitoring Instrument (OMI) on board the Earth Observing Satellite (EOS) Aura, and the OMPS (Ozone Mapping and Profiler Suite) instrument on the Suomi National Polar-orbiting Partnership satellite (Suomi NPP). Other observational results will be shown to complement these satellite data. The 2017 ozone hole metrics will be compared to the historical metrics, and these will be linearly regressed against Equivalent Effective Stratospheric Chlorine (EESC) data that are based entirely on Cape Grim Air Archive, Antarctic firn and AGAGE global measurements of ozone depleting substances (ODS). The year-to-year variability of the ozone hole does not reflect variations in the level of ODSs in the Antarctic stratosphere, which, based on surface observations, have fallen approximately 11% since their peak around 2000, or have fallen by approximately 20% since their peak around 2000 relative to 1980 levels of ODSs. The decadal variations in the ozone hole do reflect the long-term changes of ODSs in the Antarctic stratosphere and the results shown here suggest that ozone hole recovery has commenced.