Preconditions for the ozone hole decrease in 2017

Abstract

The ozone hole over Antarctica in the spring months of September–November 2017 was one of the smallest during the period of its existence. The analysis of the annual preconditions for the formation of the ozone hole, made by the authors earlier, determined the criterion for estimation of its possible state in the next spring season. The criterion is the amplitude of planetary waves in the stratospheric temperature averaged for August (last month of the Antarctic winter). Dynamical disturbances caused by planetary waves in the winter months make a significant contribution to the variations in ozone losses in the spring. Already in the late August 2017, a conclusion was made on the possible ozone hole weakening in the following months to about the third smallest value of its area in the past two decades. Satellite observations have confirmed a significant decrease in the ozone hole area and stratospheric ozone losses in the southern polar region in 2017. The results of the work are important not only for predicting anomalous ozone losses in the spring months, but also for estimations of possible changes in ultraviolet radiation that reaches the surface and influences the ecosystem of the seas and oceans in the subantarctic zone.