Trends in Antarctic ozone hole metrics 2001–17

Linear trends over the years 2001–17 are reported of a number of standard metrics used to describe the severity of the Antarctic ozone hole, both with and without a simple adjustment to account for meteorological variability. The trends were compared to those from the years 1979–2001. All metrics considered showed a trend towards reduced ozone depletion since 2001, at significance levels ranging from 2.4 to 3.9 standard errors of the trend after the adjustment was performed. The adjustment for meteorological variability had little effect on the values of the trends but did substantially reduce the scatter and, therefore, uncertainty of the trends.