Chemistry of Stratospheric Ozone Depletion Including Possible Mechanisms Underlying the Antarctic Ozone Hole

1989 ◽  
pp. 355-363
Author(s):  
G.D. Hayman
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).


2017 ◽  
Author(s):  
Sweta Shah ◽  
Olaf Tuinder ◽  
Jacob van Peet ◽  
Adrianus de Laat ◽  
Piet Stammes

Abstract. The depletion of the Antarctic ozone layer and its changing vertical distribution has been monitored closely by satellites in the past decades ever since the Antarctic ozone hole was discovered in the 1980's. Ozone profile retrieval from nadir-viewing satellites operating in the ultraviolet-visible range requires accurate calibration of level-1 (L1) radiance data. Here we study the effects of calibration on the derived level-2 (L2) ozone profiles and apply the retrieval to the Antarctic ozone hole region. We retrieve nadir ozone profiles from the SCIAMACHY instrument that flew on-board Envisat using the Ozone ProfilE Retrieval Algorithm) (OPERA) developed at KNMI with a focus on the stratospheric ozone. We study and assess the quality of these profiles and compare retrieved (L2) products from L1 SCIAMACHY versions 7 and 8 indicated as respectively (v7, v8) data from the years 2003–2011 without further radiometric correction. From validation of the profiles against ozone sonde measurements, we find that the v8 performs better due to correction for the scan-angle dependency of the instrument's optical degradation. The instrument spectral response function can still be improved for the L1 v8 data with a shift and squeeze. We find that the contribution from this improvement is a few percent residue reduction compared to a reference in the solar irradiance spectra. Validation for the years 2003 and 2009 with ozone sondes shows deviations of SCIAMACHY ozone profiles of 0.8 %–15 % in the stratosphere and 2.5 %–100 % in the troposphere, depending on the latitude and the L1 version used. Using L1 v8 for the years 2003–2011 leads to deviations of ~ 1 %–11 % in stratospheric ozone and ~ 1 %–45 % in tropospheric ozone. Application of SCIAMACHY v8 data on the Antarctic ozone hole shows that most ozone is depleted in the latitude range from 70° S to 90° S. The minimum integrated ozone column consistently occurs around 15 September for the years 2003–2011. Furthermore from the ozone profiles for all these years we observe that the value of ozone column per layer reduces to almost zero at a pressure of 100 hPa in the latitude range of 70° S to 90° S, as was found from other observations.


2019 ◽  
Vol 69 (1) ◽  
pp. 29
Author(s):  
Andrew R. Klekociuk ◽  
Matthew B. Tully ◽  
Paul B. Krummel ◽  
Oleksandr Evtushevsky ◽  
Volodymyr Kravchenko ◽  
...  

We review the 2017 Antarctic ozone hole, making use of various meteorological reanalyses, and in-situ, satellite and ground-based measurements of ozone and related trace gases, and ground-based measurements of ultraviolet radiation. The 2017 ozone hole was associated with relatively high-ozone concentrations over the Antarctic region compared to other years, and our analysis ranked it in the smallest 25% of observed ozone holes in terms of size. The severity of stratospheric ozone loss was comparable with that which occurred in 2002 (when the stratospheric vortex exhibited an unprecedented major warming) and most years prior to 1989 (which were early in the development of the ozone hole). Disturbances to the polar vortex in August and September that were associated with intervals of anomalous planetary wave activity resulted in significant erosion of the polar vortex and the mitigation of the overall level of ozone depletion. The enhanced wave activity was favoured by below-average westerly winds at high southern latitudes during winter, and the prevailing easterly phase of the quasi-biennial oscillation (QBO). Using proxy information on the chemical make-up of the polar vortex based on the analysis of nitrous oxide and the likely influence of the QBO, we suggest that the concentration of inorganic chlorine, which plays a key role in ozone loss, was likely similar to that in 2014 and 2016, when the ozone hole was larger than that in 2017. Finally, we found that the overall severity of Antarctic ozone loss in 2017 was largely dictated by the timing of the disturbances to the polar vortex rather than interannual variability in the level of inorganic chlorine.


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.


1988 ◽  
Vol 15 (2) ◽  
pp. 101-115 ◽  
Author(s):  
F. Sherwood Rowland

The momentous subject of chlorofluorocarbons (CFCs) and their effect on The Biosphere's stratospheric ozone shield is treated rather generally but in sufficient depth where necessary in three main sections dealing with (i) scientific background and current status of ongoing investigation, (ii) the major technological uses of CFCs and available or foreseeable alternatives to them, and (iii) the policy status and regulatory activity involving present or proposed future restrictions in CFC emissions.It being unlikely that life, at least as we know it, would have developed on Earth without an ozone layer in the stratosphere to ‘filter off’ harmful ultraviolet rays from solar radiation, the prospect of continuing manufacture in developing countries of its destroyers is highly alarming, especially as these destructive CFCs may take more than a decade from emission to reach the levels around 40 km altitude at which they do the most harm.


2016 ◽  
Author(s):  
Rafael P. Fernandez ◽  
Douglas E. Kinnison ◽  
Jean-Francois Lamarque ◽  
Simone Tilmes ◽  
Alfonso Saiz-Lopez

Abstract. Active bromine released from the photochemical decomposition of biogenic very short-lived bromocarbons (VSLBr) enhances stratospheric ozone depletion. Based on a dual set of 1960–2100 coupled chemistry-climate simulations (i.e. with and without VSLBr), we show that the maximum Antarctic ozone hole depletion increases by up to 14 % when natural VSLBr are considered, in better agreement with ozone observations. The impact of the additional 5 pptv VSLBr on Antarctic ozone is most evident in the periphery of the ozone hole, producing an expansion of the ozone hole area of ~5 million km2, which is equivalent in magnitude to the recently estimated Antarctic ozone healing due to the implementation of the Montreal Protocol. We find that the inclusion of VSLBr in CAM-Chem does not introduce a significant delay of the modelled ozone return date to 1980 October levels, but instead affect the depth and duration of the simulated ozone hole. Our analysis further shows that total bromine-catalysed ozone destruction in the lower stratosphere surpasses that of chlorine by year 2070, and indicates that natural VSLBr chemistry would dominate Antarctic ozone seasonality before the end of the 21st century. This work suggests a large influence of biogenic bromine on the future Antarctic ozone layer.


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