scholarly journals Antarctic ozone depletion measured by balloonsondes at Maitri - 1992

MAUSAM ◽  
2021 ◽  
Vol 48 (3) ◽  
pp. 443-446
Author(s):  
S.K. PESIHN ◽  
P. RAJESH RAO ◽  
S.K. SRIVASTAV
Keyword(s):  
Ozone Depletion ◽  
Vertical Structure ◽  
Ozone Layer ◽  
Stages Of Development ◽  
Austral Spring ◽  
Antarctic Ozone ◽  
The Antarctic

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.    

scholarly journals Evolution of the eastward shift in the quasi-stationary minimum of the Antarctic total ozone column

2016 ◽  
Author(s):  
Asen Grytsai ◽  
Gennadi Milinevsky ◽  
Andrew Klekociuk ◽  
Oleksandr Evtushevsky
Keyword(s):  
Ozone Depletion ◽  
Total Ozone ◽  
Regional Climate ◽  
Southern Annular Mode ◽  
Reanalysis Data ◽  
Austral Spring ◽  
Annular Mode ◽  
Antarctic Ozone ◽  
The Antarctic ◽  
Ozone Column

Abstract. The quasi-stationary pattern of the Antarctic total ozone has changed during the last four decades, demonstrating an eastward shift in the zonal ozone minimum. In this work, the association between the longitudinal shift of the zonal ozone minimum and changes in meteorological fields in austral spring (September–November) for 1979–2014 is analyzed. Regressive, correlative and anomaly composite analyses are applied to reanalysis data. Patterns of the Southern Annular Mode and quasi-stationary zonal waves 1 and 3 in the meteorological fields show relationships with interannual variability in the longitude of the zonal ozone minimum. On decadal time scales, consistent longitudinal shifts of the zonal ozone minimum and zonal wave 3 pattern in the middle troposphere temperature at the southern mid-latitudes are shown. As known, Antarctic ozone depletion in spring is strongly projected on the Southern Annular Mode in summer and impacts tropospheric climate. The results of this study suggest that changes in zonal ozone asymmetry accompanying the ozone depletion could be associated with regional climate changes in the Southern Hemisphere in spring.

scholarly journals Estimation of Antarctic ozone loss from ground-based total column measurements

2010 ◽  
Vol 10 (14) ◽  
pp. 6569-6581 ◽  
Author(s):  
J. Kuttippurath ◽  
F. Goutail ◽  
J.-P. Pommereau ◽  
F. Lefèvre ◽  
H. K. Roscoe ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Sensitivity Study ◽  
Satellite Measurements ◽  
Macquarie Island ◽  
Ozone Loss ◽  
Antarctic Ozone ◽  
The Antarctic ◽  
Ozone Column ◽  
Total Column ◽  
Good Agreement

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.

scholarly journals Antarctic ozone depletion between 1960 and 1980 in observations and chemistry–climate model simulations

2016 ◽  
Vol 16 (24) ◽  
pp. 15619-15627 ◽  
Author(s):  
Ulrike Langematz ◽  
Franziska Schmidt ◽  
Markus Kunze ◽  
Gregory E. Bodeker ◽  
Peter Braesicke
Keyword(s):  
Ozone Depletion ◽  
Climate Model ◽  
Total Column Ozone ◽  
Antarctic Ozone ◽  
Climate Model Simulations ◽  
Ozone Depleting Substances ◽  
Column Ozone ◽  
The Antarctic ◽  
Total Column

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.

scholarly journals Antarctic Ozone Transport and Depletion in Austral Spring 2002

2005 ◽  
Vol 62 (3) ◽  
pp. 838-847 ◽  
Author(s):  
Peter Siegmund ◽  
Henk Eskes ◽  
Peter van Velthoven
Keyword(s):  
Mass Flux ◽  
Ozone Depletion ◽  
Antarctic Region ◽  
Austral Spring ◽  
Ozone Loss ◽  
Ozone Flux ◽  
Depletion Rate ◽  
Eddy Transport ◽  
Ozone Transport ◽  
The Antarctic

Abstract The ozone budget in the Antarctic region during the stratospheric warming in 2002 is studied, using ozone analyses from the Royal Netherlands Meteorological Institute (KNMI) ozone-transport and assimilation model called TM3DAM. The results show a strong poleward ozone mass flux during this event south of 45°S between about 20 and 40 hPa, which is about 5 times as large as the ozone flux in 2001 and 2000, and is dominated by eddy transport. Above 10 hPa, there exists a partially compensating equatorward ozone flux, which is dominated by the mean meridional circulation. During this event, not only the ozone column but also the ozone depletion rate in the Antarctic region, computed as a residual from the total ozone tendency and the ozone mass flux into this region, is large. The September–October integrated ozone depletion in 2002 is similar to that in 2000 and larger than that in 2001. Simulations for September 2002 with and without ozone assimilation and parameterized ozone chemistry indicate that the parameterized ozone chemistry alone is able to produce the evolution of the ozone layer in the Antarctic region in agreement with observations. A comparison of the ozone loss directly computed from the model’s chemistry parameterization with the residual ozone loss in a simulation with parameterized chemistry but without ozone assimilation shows that the numerical error in the residual ozone loss is small.

scholarly journals Indicators of Antarctic ozone depletion: 1979 to 2019

2020 ◽  
Author(s):  
Greg E. Bodeker ◽  
Stefanie Kremser
Keyword(s):  
Ozone Depletion ◽  
Learning Algorithm ◽  
Total Column Ozone ◽  
Secular Variability ◽  
Antarctic Ozone ◽  
Time Changes ◽  
Ozone Depleting Substances ◽  
Winter Time ◽  
Column Ozone ◽  
The Antarctic

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.

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 ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Ozone Depletion ◽  
Volcanic Eruption ◽  
Stratospheric Aerosol ◽  
Satellite Observations ◽  
Ozone Hole ◽  
Maximum Area ◽  
Antarctic Ozone ◽  
The Antarctic ◽  
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).

scholarly journals Report of a large depletion in the ozone layer over southern Brazil and Uruguay by using multi-instrumental data

2018 ◽  
Vol 36 (2) ◽  
pp. 405-413 ◽  
Author(s):  
Caroline Bresciani ◽  
Gabriela Dornelles Bittencourt ◽  
José Valentin Bageston ◽  
Damaris Kirsch Pinheiro ◽  
Nelson Jorge Schuch ◽  
...  
Keyword(s):  
Ozone Concentration ◽  
Ozone Layer ◽  
Ozone Hole ◽  
Secondary Effect ◽  
Air Mass ◽  
Brewer Spectrophotometer ◽  
Antarctic Ozone ◽  
The Antarctic ◽  
Santa Maria ◽  
Antarctic Ozone Hole

Abstract. Ozone is one of the chemical compounds that form part of the atmosphere. It plays a key role in the stratosphere where the “ozone layer” is located and absorbs large amounts of ultraviolet radiation. However, during austral spring (August–November), there is a massive destruction of the ozone layer, which is known as the “Antarctic ozone hole”. This phenomenon decreases ozone concentration in that region, which may affect other regions in addition to the polar one. This anomaly may also reach mid-latitudes; hence, it is called the “secondary effect of the Antarctic ozone hole”. Therefore, this study aims to identify the passage of an ozone secondary effect (OSE) event in the region of the city of Santa Maria – RS (29.68∘ S, 53.80∘ W) by means of a multi-instrumental analysis using the satellites TIMED/SABER, AURA/MLS, and OMI-ERS. Measurements were made in São Martinho da Serra/RS – Brazil (29.53∘ S, 53.85∘ W) using a sounding balloon and a Brewer Spectrophotometer. In addition, the present study aims to describe and analyse the influence that this stratospheric ozone reduction has on temperatures presented by these instruments, including data collected through the radio occultation technique. The event was first identified by the AURA/MLS satellite on 19 October 2016 over Uruguay. This reduction in ozone concentration was found by comparing the climatology for the years 1996–1998 for the state of Rio Grande do Sul, which is close to Uruguay. This event was already observed in Santa Maria/RS-Brazil on 20 October 2016 as presented by the OMI-ERS satellite and the Brewer Spectrophotometer. Moreover, a significant decrease was reported by the TIMED/SABER satellite in Uruguay. On 21 October, the poor ozone air mass was still over the region of interest, according to the OMI-ERS satellite, data from the sounding balloon launched in Santa Maria/RS-Brazil, and measurements made by the AURA/MLS satellite. Furthermore, the influence of ozone on the stratosphere temperature was observed during this period. Despite a continuous decrease detected in height, the temperature should have followed an increasing pattern in the stratospheric layer. Finally, the TIMED/SABER and OMI-ERS satellites showed that on 23 October, the air mass with low ozone concentration was moving away, and its layer, as well as the temperature, in the stratosphere was re-established. Keywords. Atmospheric composition and structure (middle atmosphere – composition and chemistry; instruments and techniques)

Polar ozone depletion: Current status

1991 ◽  
Vol 69 (8-9) ◽  
pp. 1110-1122 ◽  
Author(s):  
G. S. Henderson ◽  
J. C. McConnell ◽  
S. R. Beagley ◽  
W. F. J. Evans
Keyword(s):  
High Latitude ◽  
Ozone Depletion ◽  
Stratospheric Ozone ◽  
Montreal Protocol ◽  
Chemical Mechanism ◽  
The Arctic ◽  
Current Status ◽  
Austral Spring ◽  
The Antarctic ◽  
Polar Ozone

Rapid springtime depletion of column ozone (O3) is observed over the Antarctic during the austral spring. A much weaker springtime depletion is observed in the Arctic region. This depletion results from a complex chemical mechanism that involves the catalytic destruction of stratospheric ozone by chlorine. The chemical mechanism appears to operate between ~12–25 km in the colder regions of the polar winter vortices. During the polar night heterogeneous chemical reactions occur on the surface of polar stratospheric clouds that convert relatively inert reservoir Cl species such as HCl to active Cl species. These clouds form when temperatures drop below about 197 K and are ubiquitous throughout the polar winter region. At polar sunrise the reactive Cl species are photolysed, liberating large quantities of free Cl that subsequently catalytically destroys O3 with a mechanism involving the formation of the Cl2O2 dimer. The magnitude of the spring depletion is much greater in the Antarctic relative to the Arctic owing to the greater stability and longer duration of the southern polar vortex. Breakup of the intense high-latitude vortices in late (Antarctic) or early (Arctic) spring results in infilling of the ozone holes but adversely affects midlatitude ozone levels by diluting them with O3-depleted, ClO-rich high-latitude air. The magnitude of the Antarctic ozone depletion has been increasing since 1979 and its current depletion in October 1990 amounts to 60%. The increase in the size of the depletion is anticorrelated with increasing anthropogenic chlorofluorocarbon (CFCs) release. Adherence to the revised Montréal Protocol should result in a reduction of stratospheric halogen levels with subsequent amelioration of polar ozone depletion but the time constant for the atmosphere to return to pre-CFC levels is ~60–100 years.

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