The Antarctic ozone hole during 2012

first_imgWe review the 2012 Antarctic ozone hole, making use of various meteorologicalreanalyses, remotely sensed ozone measurements and ground-based measurementsof ultra-violet radiation. Based on analysis of 33 years of satellite records,we find that the ozone hole of 2012 was one of the least severe since the late1980s in terms of maximum area, minimum ozone level and total ozone deficit.In particular, the estimated integrated ozone mass effectively depleted within theozone hole of 2012 was approximately 720 Mt, which is the 12th smallest deficiton record and 28 per cent of the peak deficit observed in 2006. The key factor inlimiting the extent of Antarctic ozone loss in 2012 was the relatively warm temperaturesthat occurred in the Antarctic stratosphere from early July. These warmtemperatures, which were driven by dynamical activity, limited the activation ofozone depletion chemistry within the polar vortex during the latter part of thepolar winter. Additionally, dynamical disturbances to the polar cap region duringspring were aided by the prevailing phase of the Quasi-Biennial Oscillation (QBO)which was strongly negative (westward) and favouring the poleward propagationof heat flux anomalies; these disturbances resulted in the steady erosion of thevortex and caused it to breakdown relatively early compared to recent years. Themetrics for the Antarctic ozone hole of 2012 showed some similarity with thoseof 1988 and 2002 (which were years of anomalously small ozone holes) despite allthree years having distinctly different QBO indices indicating variant strengths ofthe polar vortex (and severity of ozone loss).last_img

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