Overview of the Antarctic ozone depletion issue

1986 ◽  
Vol 13 (12) ◽  
pp. 1191-1192 ◽  
Author(s):  
Mark R. Schoeberl ◽  
Arlin J. Krueger
2010 ◽  
Vol 10 (14) ◽  
pp. 6569-6581 ◽  
Author(s):  
J. Kuttippurath ◽  
F. Goutail ◽  
J.-P. Pommereau ◽  
F. Lefèvre ◽  
H. K. Roscoe ◽  
...  

Abstract. The passive tracer method is used to estimate ozone loss from ground-based measurements in the Antarctic. A sensitivity study shows that the ozone depletion can be estimated within an accuracy of ~4%. The method is then applied to the ground-based observations from Arrival Heights, Belgrano, Concordia, Dumont d'Urville, Faraday, Halley, Marambio, Neumayer, Rothera, South Pole, Syowa, and Zhongshan for the diagnosis of ozone loss in the Antarctic. On average, the ten-day boxcar average of the vortex mean ozone column loss deduced from the ground-based stations was about 55±5% in 2005–2009. The ozone loss computed from the ground-based measurements is in very good agreement with those derived from satellite measurements (OMI and SCIAMACHY) and model simulations (REPROBUS and SLIMCAT), where the differences are within ±3–5%. The historical ground-based total ozone observations in October show that the depletion started in the late 1970s, reached a maximum in the early 1990s and stabilised afterwards due to saturation. There is no indication of ozone recovery yet. At southern mid-latitudes, a reduction of 20–50% is observed for a few days in October–November at the newly installed Rio Gallegos station. Similar depletion of ozone is also observed episodically during the vortex overpasses at Kerguelen in October–November and at Macquarie Island in July–August of the recent winters. This illustrates the significance of measurements at the edges of Antarctica.


2016 ◽  
Vol 16 (24) ◽  
pp. 15619-15627 ◽  
Author(s):  
Ulrike Langematz ◽  
Franziska Schmidt ◽  
Markus Kunze ◽  
Gregory E. Bodeker ◽  
Peter Braesicke

Abstract. The year 1980 has often been used as a benchmark for the return of Antarctic ozone to conditions assumed to be unaffected by emissions of ozone-depleting substances (ODSs), implying that anthropogenic ozone depletion in Antarctica started around 1980. Here, the extent of anthropogenically driven Antarctic ozone depletion prior to 1980 is examined using output from transient chemistry–climate model (CCM) simulations from 1960 to 2000 with prescribed changes of ozone-depleting substance concentrations in conjunction with observations. A regression model is used to attribute CCM modelled and observed changes in Antarctic total column ozone to halogen-driven chemistry prior to 1980. Wintertime Antarctic ozone is strongly affected by dynamical processes that vary in amplitude from year to year and from model to model. However, when the dynamical and chemical impacts on ozone are separated, all models consistently show a long-term, halogen-induced negative trend in Antarctic ozone from 1960 to 1980. The anthropogenically driven ozone loss from 1960 to 1980 ranges between 26.4 ± 3.4 and 49.8 ± 6.2 % of the total anthropogenic ozone depletion from 1960 to 2000. An even stronger ozone decline of 56.4 ± 6.8 % was estimated from ozone observations. This analysis of the observations and simulations from 17 CCMs clarifies that while the return of Antarctic ozone to 1980 values remains a valid milestone, achieving that milestone is not indicative of full recovery of the Antarctic ozone layer from the effects of ODSs.


2020 ◽  
Author(s):  
Greg E. Bodeker ◽  
Stefanie Kremser

Abstract. The National Institute of Water and Atmospheric Research/Bodeker Scientific (NIWA-BS) total column ozone (TCO) database, and the associated BS-filled TCO database, have been updated to cover the period 1979 to 2019, bringing both to version 3.5.1 (V3.5.1). The BS-filled database builds on the NIWA-BS database by using a machine-learning algorithm to fill spatial and temporal data gaps to provide gap-free TCO fields over Antarctic. These filled TCO fields then provide a more complete picture of winter-time changes in the ozone layer over Antarctica. The BS-filled database has been used to calculate continuous, homogeneous time series of indicators of Antarctic ozone depletion from 1979 to 2019, including (i) daily values of the ozone mass deficit based on TCO below a 220 DU threshold, (ii) daily measures of the area over Antarctica where TCO levels are below 150 DU, below 220 DU, more than 30 % below 1979 to 1981 climatological means, and more than 50 % below 1979 to 1981 climatological means, (iii) the date of disappearance of 150 DU TCO values, 220 DU TCO values, values 30 % or more below 1979 to 1981 climatological means, and values 50 % or more below 1979 to 1981 climatological means, for each year, and (iv) daily minimum TCO values over the range 75° S to 90° S equivalent latitude. Since both the NIWA-BS and BS-filled databases provide uncertainties on every TCO value, the Antarctic ozone depletion metrics are provided, for the first time, with fully traceable uncertainties. To gain insight into how the vertical distribution of ozone over Antarctica has changed over the past 36 years, ozone concentrations, combined and homogenized from several satellite-based ozone monitoring instruments as well as the global ozonesonde network, were also analysed. A robust attribution to changes in the drivers of long-term secular variability in these metrics has not been performed in this analysis. As a result, statements about the recovery of Antarctic TCO from the effects of ozone depleting substances cannot be made. That said, there are clear indications of a change in trend in many of the metrics reported on here around the turn of the century, close to when Antarctic stratospheric concentrations of chlorine and bromine peaked.


MAUSAM ◽  
2021 ◽  
Vol 48 (3) ◽  
pp. 443-446
Author(s):  
S.K. PESIHN ◽  
P. RAJESH RAO ◽  
S.K. SRIVASTAV

ABSTRACT. Profiles from a series of balloon borne ozonesonde ascents are used to chart the development of the Antarctic depletion over Maitri in the austral spring of 1992. The vertical structure of the ozone layer is discussed, including the presence of stratification, which occurs at all stages of development. The main feature of 1992 ozonesonde flights is depletion of 97% in the months of September and October between 15-23 km, which is unique.    


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).


1991 ◽  
Vol 3 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Deneb Karentz

Springtime ozone depletion over Antarctica has been observed for over a decade. Associated with ozone depletion is an increase in the levels of biologically harmful ultraviolet-B (UV-B) that reach the earth's surface, a situation that has prompted much controversy about the ecological effects of this atmospheric phenomenon on Antarctic ecosystems. A major hindrance to assessing the ecological impact is lack of appropriate data on Antarctic systems before the present ozone depletion cycle began. In addition, certain physical features of the Antarctic environment (clouds, snow and ice) and the UV-B photobiology (repair processes and protective strategies) of endemic species can alter the potential biological effects of this environmental stress in, as yet, undetermined ways. Increases in incident UV levels will most likely result in changes in the taxonomic structure of communities. The effects of these changes on net productivity and trophic dynamics cannot be accurately assessed without quantifying ambient doeses of UV and characterizing the UV photobiology of individual species. Both the physical features of the springtime environment and the biological responses of endemic species must be considered in future research efforts to evaluate the biological consequences of the Antarctic ozone hole.


2012 ◽  
Vol 12 (10) ◽  
pp. 28451-28466
Author(s):  
P. E. Huck ◽  
G. E. Bodeker ◽  
S. Kremser ◽  
A. J. McDonald ◽  
M. Rex ◽  
...  

Abstract. Two semi-empirical models were developed for the Antarctic stratosphere to relate the shift of species within total chlorine (Cly = HCl + ClONO2 + HOCl + 2 × Cl2 + 2 × Cl2O2 + ClO + Cl) into the active forms (here: ClOx = 2 × Cl2O2 + ClO), and to relate the rate of ozone destruction to ClOx. These two models provide a fast and computationally inexpensive way to describe the inter- and intra-annual evolution of ClOx and ozone mass deficit (OMD) in the Antarctic spring. The models are based on the underlying physics/chemistry of the system and capture the key chemical and physical processes in the Antarctic stratosphere that determine the interaction between climate change and Antarctic ozone depletion. They were developed considering bulk effects of chemical mechanisms for the duration of the Antarctic vortex period and quantities averaged over the vortex area. The model equations were regressed against observations of daytime ClO and OMD providing a set of empirical fit coefficients. Both semi-empirical models are able to explain much of the intra- and inter-annual variability observed in daily ClOx and OMD time series. This proof-of-concept paper outlines the semi-empirical approach to describing the evolution of Antarctic chlorine activation and ozone depletion.


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.


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