scholarly journals The Antarctic ozone hole during 2015 and 2016

2019 ◽  
Vol 69 (1) ◽  
pp. 16
Author(s):  
Matthew B. Tully ◽  
Andrew R. Klekociuk ◽  
Paul B. Krummel ◽  
H. Peter Gies ◽  
Simon P. Alexander ◽  
...  

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).

2012 ◽  
Vol 26 (2) ◽  
pp. 662-668 ◽  
Author(s):  
Andrew Orr ◽  
Thomas J. Bracegirdle ◽  
J. Scott Hosking ◽  
Wuhu Feng ◽  
Howard K. Roscoe ◽  
...  

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.


1992 ◽  
Vol 97 (D8) ◽  
pp. 8075 ◽  
Author(s):  
Giovanni Pitari ◽  
Guido Visconti ◽  
Marco Verdecchia

2019 ◽  
Vol 69 (1) ◽  
pp. 52
Author(s):  
Matthew B. Tully ◽  
Paul B. Krummel ◽  
Andrew R. Klekociuk

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.


Nature ◽  
2019 ◽  
Vol 575 (7781) ◽  
pp. 46-47 ◽  
Author(s):  
Susan Solomon

2011 ◽  
Vol 11 (5) ◽  
pp. 1961-1977 ◽  
Author(s):  
J. Flemming ◽  
A. Inness ◽  
L. Jones ◽  
H. J. Eskes ◽  
V. Huijnen ◽  
...  

Abstract. The 2008 Antarctic ozone hole was one of the largest and most long-lived in recent years. Predictions of the ozone hole were made in near-real time (NRT) and hindcast mode with the Integrated Forecast System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF). The forecasts were carried out both with and without assimilation of satellite observations from multiple instruments to provide more realistic initial conditions. Three different chemistry schemes were applied for the description of stratospheric ozone chemistry: (i) a linearization of the ozone chemistry, (ii) the stratospheric chemical mechanism of the Model of Ozone and Related Chemical Tracers, version 3, (MOZART-3) and (iii) the relaxation to climatology as implemented in the Transport Model, version 5, (TM5). The IFS uses the latter two schemes by means of a two-way coupled system. Without assimilation, the forecasts showed model-specific shortcomings in predicting start time, extent and duration of the ozone hole. The assimilation of satellite observations from the Microwave Limb Sounder (MLS), the Ozone Monitoring Instrument (OMI), the Solar Backscattering Ultraviolet radiometer (SBUV-2) and the SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) led to a significant improvement of the forecasts when compared with total columns and vertical profiles from ozone sondes. The combined assimilation of observations from multiple instruments helped to overcome limitations of the ultraviolet (UV) sensors at low solar elevation over Antarctica. The assimilation of data from MLS was crucial to obtain a good agreement with the observed ozone profiles both in the polar stratosphere and troposphere. The ozone analyses by the three model configurations were very similar despite the different underlying chemistry schemes. Using ozone analyses as initial conditions had a very beneficial but variable effect on the predictability of the ozone hole over 15 days. The initialized forecasts with the MOZART-3 chemistry produced the best predictions of the increasing ozone hole whereas the linear scheme showed the best results during the ozonehole closure.


2004 ◽  
Vol 31 (21) ◽  
pp. n/a-n/a ◽  
Author(s):  
Paul A. Newman ◽  
S. Randolph Kawa ◽  
Eric R. Nash

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