scholarly journals The 2020 Arctic ozone depletion and signs of its effect on the ozone column at lower latitudes

2021 ◽  
Vol 2 (1-4) ◽  
Author(s):  
Boyan Petkov ◽  
Vito Vitale ◽  
Piero Di Carlo ◽  
Mauro Mazzola ◽  
Angelo Lupi ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Ozone Column

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 GUV long-term measurements of total ozone column and effective cloud transmittance at three Norwegian sites

2021 ◽  
Vol 21 (10) ◽  
pp. 7881-7899
Author(s):  
Tove M. Svendby ◽  
Bjørn Johnsen ◽  
Arve Kylling ◽  
Arne Dahlback ◽  
Germar H. Bernhard ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Total Ozone ◽  
Monitoring Network ◽  
High Time Resolution ◽  
Data Sets ◽  
Total Ozone Column ◽  
Ice Melt ◽  
Arctic Ice ◽  
Ozone Column

Abstract. Measurements of total ozone column and effective cloud transmittance have been performed since 1995 at the three Norwegian sites Oslo/Kjeller, Andøya/Tromsø, and in Ny-Ålesund (Svalbard). These sites are a subset of nine stations included in the Norwegian UV monitoring network, which uses ground-based ultraviolet (GUV) multi-filter instruments and is operated by the Norwegian Radiation and Nuclear Safety Authority (DSA) and the Norwegian Institute for Air Research (NILU). The network includes unique data sets of high-time-resolution measurements that can be used for a broad range of atmospheric and biological exposure studies. Comparison of the 25-year records of GUV (global sky) total ozone measurements with Brewer direct sun (DS) measurements shows that the GUV instruments provide valuable supplements to the more standardized ground-based instruments. The GUV instruments can fill in missing data and extend the measuring season at sites with reduced staff and/or characterized by harsh environmental conditions, such as Ny-Ålesund. Also, a harmonized GUV can easily be moved to more remote/unmanned locations and provide independent total ozone column data sets. The GUV instrument in Ny-Ålesund captured well the exceptionally large Arctic ozone depletion in March/April 2020, whereas the GUV instrument in Oslo recorded a mini ozone hole in December 2019 with total ozone values below 200 DU. For all the three Norwegian stations there is a slight increase in total ozone from 1995 until today. Measurements of GUV effective cloud transmittance in Ny-Ålesund indicate that there has been a significant change in albedo during the past 25 years, most likely resulting from increased temperatures and Arctic ice melt in the area surrounding Svalbard.

scholarly journals The influence of polar vortex ozone depletion on NH mid-latitude ozone trends in spring

2006 ◽  
Vol 6 (10) ◽  
pp. 2837-2845 ◽  
Author(s):  
S. B. Andersen ◽  
B. M. Knudsen
Keyword(s):  
Lower Limit ◽  
Ozone Depletion ◽  
Total Ozone ◽  
Polar Vortex ◽  
Major Fraction ◽  
Total Ozone Column ◽  
Trajectory Calculations ◽  
Ozone Trends ◽  
Decadal Variations ◽  
Ozone Column

Abstract. Reverse domain-filling trajectory calculations have been performed for the years 1993, 1995, 1996, 1997, and 2000 to calculate the spreading of ozone depleted air from the polar vortex to midlatitudes in spring. We find that for these years with massive Arctic ozone depletion the zonal mean total ozone column at midlatitudes is reduced with between 7 and 12 DU in the April-May period. The polar vortex and remnants have preferred locations which leads to longitudinal differences in the midlatitude ozone trends. Together with decadal variations in circulation the dilution of ozone depleted air may explain the major fraction of longitudinal differences in midlatitude ozone trends. For the period 1979–1997 the dilution may explain 50% of the longitudinal differences in ozone trends and for the period 1979–2002 it may explain 45%. The dilution also has a significant impact on the zonal mean ozone trends in the April-May period. Although uncertainties are large due to uncertainties in the ozone depletion values and neglect of ozone depletion in other years than 1993, 1995, 1996, 1997, and 2000 we have tried to calculate the size of this effect. We estimate that dilution may explain 29% of the trend in the period 1979–1997 and 33% of the trend in the period 1979–2002 as a lower limit.

scholarly journals Influence of the Change in Total Ozone Column (TOC) on the Occurrence of Tropospheric Ozone Depletion Events (ODEs) in the Antarctic

2021 ◽  
Author(s):  
Le Cao ◽  
Linjie Fan ◽  
Simeng Li ◽  
Shuangyan Yang
Keyword(s):  
Observational Data ◽  
Ozone Depletion ◽  
Tropospheric Ozone ◽  
Total Ozone ◽  
Numerical Models ◽  
Total Ozone Column ◽  
Speed Up ◽  
The Antarctic ◽  
The Impact ◽  
Ozone Column

Abstract. The occurrence of the tropospheric ozone depletion events (ODEs) in the Antarctic can be influenced by the change in Total Ozone Column (TOC). In this study, we combined the observational data obtained from ground observation stations with two numerical models (TUV and KINAL), to figure out the relationship between the TOC change and the occurrence of ODEs in the Antarctic. A sensitivity analysis was also performed on the change in ozone and major bromine species (BrO, HOBr and HBr) to find out key photolysis reactions determining the impact on the occurrence of tropospheric ODEs brought by the change in TOC. From the analysis of the observational data and the numerical results, we suggested that the occurrence frequency of ODEs in the Antarctic seems negatively correlated with the variation of TOC. Moreover, major ODE accelerating reactions (i.e. photolysis of ozone, H2O2 and HCHO) and decelerating reactions (i.e. photolysis of BrO and HOBr), which heavily control the start of ODEs, were also identified. It was found that when TOC varies, the major ODE accelerating reactions speed up significantly, while major ODE decelerating reactions are only slightly affected, thus leading to the negative dependence of the ODE occurrence on the change in TOC.

scholarly journals Seasonal impact of biogenic very short-lived bromocarbons on lowermost stratospheric ozone between 60° N and 60° S during the 21st century

2020 ◽  
Vol 20 (13) ◽  
pp. 8083-8102
Author(s):  
Javier Alejandro Barrera ◽  
Rafael Pedro Fernandez ◽  
Fernando Iglesias-Suarez ◽  
Carlos Alberto Cuevas ◽  
Jean-Francois Lamarque ◽  
...  
Keyword(s):  
21St Century ◽  
Ozone Depletion ◽  
Hemispheric Asymmetry ◽  
Stratospheric Ozone ◽  
Ozone Loss ◽  
Seasonal Impact ◽  
Low Sensitivity ◽  
The Tropics ◽  
The Impact ◽  
Ozone Column

Abstract. Biogenic very short-lived bromocarbons (VSLBr) currently represent ∼25 % of the total stratospheric bromine loading. Owing to their much shorter lifetime compared to anthropogenic long-lived bromine (e.g. halons) and chlorine (e.g. chlorofluorocarbons), the impact of VSLBr on ozone peaks in the lowermost stratosphere, which is a key climatic and radiative atmospheric region. Here we present a modelling study of the evolution of stratospheric ozone and its chemical loss within the tropics and at mid-latitudes during the 21st century. Two different experiments are explored: considering and neglecting the additional stratospheric injection of 5 ppt biogenic bromine naturally released from the ocean. Our analysis shows that the inclusion of VSLBr results in a realistic stratospheric bromine loading and improves the agreement between the model and satellite observations of the total ozone column (TOC) for the 1980–2015 period at mid-latitudes. We show that the overall ozone response to VSLBr at mid-latitudes follows the stratospheric evolution of long-lived inorganic chlorine and bromine throughout the 21st century. Additional ozone loss due to VSLBr is maximized during the present-day period (1990–2010), with TOC differences of −8 DU (−3 %) and −5.5 DU (−2 %) for the Southern Hemisphere and Northern Hemisphere mid-latitudes (SH-MLs and NH-MLs), respectively. Moreover, the projected TOC differences at the end of the 21st century are ∼50 % lower than the values found for the present-day period. We find that seasonal VSLBr impact on lowermost stratospheric ozone at mid-latitude is influenced by the seasonality of the heterogeneous inorganic-chlorine reactivation processes on ice crystals. Indeed, due to the more efficient reactivation of chlorine reservoirs (mainly ClONO2 and HCl) within the colder SH-ML lowermost stratosphere, the seasonal VSLBr impact shows a small but persistent hemispheric asymmetry through the whole modelled period. Our results indicate that, although the overall VSLBr-driven ozone destruction is greatest during spring, the halogen-mediated (Halogx-Loss) ozone loss cycle in the mid-latitude lowermost stratosphere during winter is comparatively more efficient than the HOx cycle with respect to other seasons. Indeed, when VSLBr are considered, Halogx-Loss dominates wintertime lowermost stratospheric ozone loss at SH-MLs between 1985 and 2020, with a contribution of inter-halogen ClOx–BrOx cycles to Halogx-Loss of ∼50 %. Within the tropics, a small (<-2.5 DU) and relatively constant (∼-1 %) ozone depletion mediated by VSLBr is closely related to their fixed emissions throughout the modelled period. By including the VSLBr sources, the seasonal Halogx-Loss contribution to lowermost stratospheric ozone loss is practically dominated by the BrOx cycle, reflecting the low sensitivity of very short-lived (VSL) bromine to background halogen abundances to drive tropical stratospheric ozone depletion. We conclude that the link between biogenic bromine sources and seasonal changes in heterogeneous chlorine reactivation is a key feature for future projections of mid-latitude lowermost stratospheric ozone during the 21st century.

scholarly journals Multiple symptoms of total ozone recovery inside the Antarctic vortex during austral spring

2018 ◽  
Vol 18 (10) ◽  
pp. 7557-7572 ◽  
Author(s):  
Andrea Pazmiño ◽  
Sophie Godin-Beekmann ◽  
Alain Hauchecorne ◽  
Chantal Claud ◽  
Sergey Khaykin ◽  
...  
Keyword(s):  
Potential Vorticity ◽  
Ozone Depletion ◽  
Total Ozone ◽  
Linear Functions ◽  
Multilinear Regression ◽  
Quasi Biennial Oscillation ◽  
Total Ozone Column ◽  
The Antarctic ◽  
Ozone Column ◽  
Mlr Model

Abstract. The long-term evolution of total ozone column inside the Antarctic polar vortex is investigated over the 1980–2017 period. Trend analyses are performed using a multilinear regression (MLR) model based on various proxies for the evaluation of ozone interannual variability (heat flux, quasi-biennial oscillation, solar flux, Antarctic oscillation and aerosols). Annual total ozone column measurements corresponding to the mean monthly values inside the vortex in September and during the period of maximum ozone depletion from 15 September to 15 October are used. Total ozone columns from the Multi-Sensor Reanalysis version 2 (MSR-2) dataset and from a combined record based on TOMS and OMI satellite datasets with gaps filled by MSR-2 (1993–1995) are considered in the study. Ozone trends are computed by a piece-wise trend (PWT) proxy that includes two linear functions before and after the turnaround year in 2001 and a parabolic function to account for the saturation of the polar ozone destruction. In order to evaluate average total ozone within the vortex, two classification methods are used, based on the potential vorticity gradient as a function of equivalent latitude. The first standard one considers this gradient at a single isentropic level (475 or 550 K), while the second one uses a range of isentropic levels between 400 and 600 K. The regression model includes a new proxy (GRAD) linked to the gradient of potential vorticity as a function of equivalent latitude and representing the stability of the vortex during the studied month. The determination coefficient (R2) between observations and modelled values increases by ∼ 0.05 when this proxy is included in the MLR model. Highest R2 (0.92–0.95) and minimum residuals are obtained for the second classification method for both datasets and months. Trends in September over the 2001–2017 period are statistically significant at 2σ level with values ranging between 1.84 ± 1.03 and 2.83 ± 1.48 DU yr−1 depending on the methods and considered proxies. This result confirms the recent studies of Antarctic ozone healing during that month. Trends from 2001 are 2 to 3 times smaller than before the turnaround year, as expected from the response to the slowly ozone-depleting substances decrease in polar regions. For the first time, significant trends are found for the period of maximum ozone depletion. Estimated trends from 2001 for the 15 September–15 October period over 2001–2017 vary from 1.21 ± 0.83 to 1.96 DU ± 0.99 yr−1 and are significant at 2σ level. MLR analysis is also applied to the ozone mass deficit (OMD) metric for both periods, considering a threshold at 220 DU and total ozone columns south of 60∘ S. Significant trend values are observed for all cases and periods. A decrease of OMD of 0.86 ± 0.36 and 0.65 ± 0.33 Mt yr−1 since 2001 is observed in September and 15 September–15 October, respectively. Ozone recovery is also confirmed by a steady decrease of the relative area of total ozone values lower than 175 DU within the vortex in the 15 September–15 October period since 2010 and a delay in the occurrence of ozone levels below 125 DU since 2005.

scholarly journals A model study of the January 2006 low total ozone episode over Western Europe and comparison with ozone sonde data

2009 ◽  
Vol 9 (17) ◽  
pp. 6429-6451 ◽  
Author(s):  
A. Mangold ◽  
J.-U. Grooß ◽  
H. De Backer ◽  
O. Kirner ◽  
R. Ruhnke ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Total Ozone ◽  
Western Europe ◽  
Transport Processes ◽  
Minor Importance ◽  
Total Ozone Column ◽  
Ozone Episodes ◽  
Ozone Episode ◽  
Ozone Column

Abstract. Total column and stratospheric ozone levels at mid-latitudes often reveal strong fluctuations on time scales of days caused by dynamic processes. In some cases the total ozone column is distinctly reduced below climatological values. Here, a very low total ozone episode around 19 January 2006 over Western Europe is investigated when the observed total ozone column over Uccle (BE), measured by a Brewer spectrophotometer, reached a daily minimum of 200 DU, the lowest recorded value at this station. In order to investigate the mechanisms leading to the ozone minimum, the present study used data from (i) six ozone sounding stations in Western and Middle Europe, (ii) ECMWF meteorological fields, (iii) a simulation of the CLaMS model for January 2006, (iv) a multi-year run of the chemistry transport model KASIMA, and (v) a six-year run of the climate chemistry model ECHAM5/MESSy1. The ozone decrease at different heights was quantified and it was determined to what extent different transport mechanisms, and instantaneous, in-situ chemical ozone depletion contributed to the event. All three models reproduced the evolution and formation of the event. The ozone column decrease between Θ=300 and 750 K was strongest at Uccle (BE) and De Bilt (NL) with 108 and 103 DU, respectively, and somewhat lower at Hohenpeissenberg (DE), Payerne (CH), Prague (CZ) and Lerwick (UK) with 85, 84, 83 and 74 DU, respectively. This analysis demonstrated that mainly the displacement of the ozone depleted polar vortex contributed to the ozone column decrease. Advection of ozone-poor low-latitude air masses was important in the UTLS region. The vertical displacement of isentropes connected with divergence of air out of the column was found to be of minor importance compared to the horizontal transport processes. Severe low total ozone episodes seem to occur when the mentioned mechanisms are superimposed. Instantaneous, in-situ chemical ozone depletion accounted for only 2±1% of the overall total ozone decrease at the sounding stations.

scholarly journals A~model study of the January 2006 low total ozone episode over Western Europe and comparison with ozone sonde data

2009 ◽  
Vol 9 (2) ◽  
pp. 6003-6060
Author(s):  
A. Mangold ◽  
J.-U. Grooß ◽  
H. De Backer ◽  
O. Kirner ◽  
R. Ruhnke ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Total Ozone ◽  
Western Europe ◽  
Stratospheric Ozone ◽  
Transport Mechanisms ◽  
Total Ozone Column ◽  
Ozone Episodes ◽  
Ozone Episode ◽  
Ozone Column

Abstract. Total column and stratospheric ozone levels at mid-latitudes often reveal strong fluctuations on time scales of days caused by dynamic processes. In some cases the total ozone column is distinctly reduced below climatological values. Here, a very low total ozone episode around 19 January 2006 over Western Europe is investigated when the observed total ozone column over Uccle (BE), measured by a Brewer spectrophotometer, reached a daily minimum of 200 DU, the lowest recorded value at this station. In order to investigate the mechanisms leading to the ozone minimum, the present study used data from (i) six ozone sounding stations in Western and Middle Europe, (ii) ECMWF meteorological fields, (iii) a simulation of the CLaMS model for January 2006, (iv) a multi-year run of the chemistry transport model KASIMA, and (v) a six-year run of the climate chemistry model ECHAM5/MESSy1. The ozone decrease at different heights was quantified and it was determined to what extent different transport mechanisms, and instantaneous, in-situ chemical ozone depletion contributed to the event. All three models reproduced well the evolution and formation of the event. The ozone column decrease between Θ=300 and 750 K was strongest at Uccle (BE) and De Bilt (NL) with 108 and 103 DU, respectively, and somewhat lower at Hohenpeissenberg (DE), Payerne (CH), Prague (CZ) and Lerwick (UK) with 85, 84, 83 and 74 DU, respectively. Our analysis demonstrated that mainly the displacement of the ozone depleted polar vortex contributed to the ozone column decrease (between 55 and 82%), compared to the advection of ozone-poor low-latitude air in the UTLS region, connected with divergence of air out of the column caused by uplift of isentropes in the lower stratosphere. This dominance was significant only at Lerwick, De Bilt and Uccle. Severe low total ozone episodes seem to occur preferentially when the two mentioned transport mechanisms occur at the same time. Instantaneous, in-situ chemical ozone depletion accounted for only 2±1% of the overall total ozone decrease at the sounding stations.

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