Global ozone depletion and the Antarctic ozone hole

We reviewed the 2015 and 2016 Antarctic ozone holes, making use of a variety of ground-based and spacebased measurements of ozone and ultraviolet radiation, supplemented by meteorological reanalyses. The ozone hole of 2015 was one of the most severe on record with respect to maximum area and integrated deficit and was notably longlasting, with many values above previous extremes in October, November and December. In contrast, all assessed metrics for the 2016 ozone hole were at or below their median values for the 37 ozone holes since 1979 for which adequate satellite observations exist. The 2015 ozone hole was influenced both by very cold conditions and enhanced ozone depletion caused by stratospheric aerosol resulting from the April 2015 volcanic eruption of Calbuco (Chile).

Download Full-text

Strong Dynamical Modulation of the Cooling of the Polar Stratosphere Associated with the Antarctic Ozone Hole

Journal of Climate ◽

10.1175/jcli-d-12-00480.1 ◽

2012 ◽

Vol 26 (2) ◽

pp. 662-668 ◽

Cited By ~ 10

Author(s):

Andrew Orr ◽

Thomas J. Bracegirdle ◽

J. Scott Hosking ◽

Wuhu Feng ◽

Howard K. Roscoe ◽

...

Keyword(s):

Ozone Depletion ◽

Model Simulation ◽

Early Summer ◽

Ozone Hole ◽

Radiative Cooling ◽

Cold Anomaly ◽

Antarctic Ozone ◽

Polar Stratosphere ◽

The Antarctic ◽

Antarctic Ozone Hole

Abstract A model simulation forced by prescribed ozone depletion shows strong dynamical modulation of the springtime cooling of the polar stratosphere associated with the Antarctic ozone hole. The authors find that in late spring the anomalous radiative cooling in response to ozone depletion is almost canceled above ~100 hPa by an increase in dynamical heating. Between ~300 and ~100 hPa, however, it is enhanced by a reduction in dynamical heating, resulting in the descent of the cold anomaly down to the tropopause. In early summer increased dynamical heating dominates as the radiative cooling diminishes so that the cold anomaly associated with the delayed breakup of the stratospheric vortex is reduced. The anomalous dynamical heating is driven by changes in the Brewer–Dobson circulation arising primarily from the dissipation of resolved-scale waves. The model changes are broadly consistent with trends from reanalysis and offline diagnoses of heating rates using a radiation scheme. These results help one to understand dynamically induced change in the evolution and timing of the stratospheric vortex in recent decades and will help to enable improved simulation of the Southern Hemisphere climate.

Download Full-text

Trends in Antarctic ozone hole metrics 2001–17

Journal of Southern Hemisphere Earth System Science ◽

10.1071/es19020 ◽

2019 ◽

Vol 69 (1) ◽

pp. 52

Author(s):

Matthew B. Tully ◽

Paul B. Krummel ◽

Andrew R. Klekociuk

Keyword(s):

Ozone Depletion ◽

Ozone Hole ◽

Standard Errors ◽

Significance Levels ◽

Antarctic Ozone ◽

The Antarctic ◽

Antarctic Ozone Hole ◽

Linear Trends

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.

Download Full-text