Dynamical and chemical processes contributing to ozone loss in
exceptional Arctic stratosphere winter-spring of 2020

Smyshlyaev, S. P.; Vargin, P. N.; Lukyanov, A.; Tsvetkova, N. D.; Motsakov, M. A.

doi:10.5194/acp-2021-11

Cited by 11 publications

(3 citation statements)

References 5 publications

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“…The stratospheric polar vortex was characterised by strong stability and very cold temperatures in the 2019-2020 winter quarter. Later, during the first half of March, the vortex started to lose stability in association with the upward propagation of tropospheric waves over the region of the Gulf of Alaska (Smyshlyaev et al 2021). As a result, the stratospheric vortex weakened and displaced over the Canadian area.…”

Section: The 2020 Springtime Ozone Column Over Europe According To Ground-based Measurementsmentioning

confidence: 99%

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

Petkov

Vitale

Carlo

et al. 2021

Bull. of Atmos. Sci.& Technol.

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The present study discusses the effect of the ozone depletion that occurred over the Arctic in 2020 on the ozone column in central and southern Europe by analysing a data set obtained from ground-based measurements at six stations placed from 79 to 42°N. Over the northernmost site (Ny-Ålesund), the ozone column decreased by about 45% compared to the climatological average at the beginning of April, and its values returned to the normal levels at the end of the month. Southwards, the anomaly gradually reduced to nearly 15% at 42°N (Rome) and the ozone minimum was detected with a delay from about 6 days at 65°N to 20 days at 42°N. At the same time, the evolution of the ozone column at the considered stations placed below the polar circle corresponded to that observed at Ny-Ålesund, but at 42°–46°N, the ozone column turned back to the typical values at the end of May. This similarity in the ozone evolutional patterns at different latitudes and the gradually increasing delay of the minimum occurrences towards the south allows the assumption that the ozone columns at lower latitudes were affected by the phenomenon in the Arctic. The ozone decrease observed at Aosta (46°N) combined with predominantly cloud-free conditions resulted in about an 18% increase in the erythemally weighted solar ultraviolet irradiance reaching the Earth’s surface in May.

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Section: The 2020 Springtime Ozone Column Over Europe According To Ground-based Measurementsmentioning

confidence: 99%

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

Petkov

Vitale

Carlo

et al. 2021

Bull. of Atmos. Sci.& Technol.

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“…Importantly, in addition to the strong perturbation of the UTLS aerosol conditions, a record-breaking ozone depletion was observed over the Arctic in the spring of 2020 (DeLand et al, 2020;Manney et al, 2020;Wohltmann et al, 2020;Inness et al, 2020;Wilka et al, 2021;Dameris et al, 2021;Smyshlyaev et al, 2021;Bognar et al, 2021). To our best knowledge, a potential impact of stratospheric aerosol on the complex chemical and meteorological processes leading to this strong ozone reduction was, however, not discussed in any of the published studies.…”

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confidence: 99%

The unexpected smoke layer in the High Arctic winter stratosphere during MOSAiC 2019–2020

et al. 2021

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Abstract. During the 1-year MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition, the German icebreaker Polarstern drifted through Arctic Ocean ice from October 2019 to May 2020, mainly at latitudes between 85 and 88.5∘ N. A multiwavelength polarization Raman lidar was operated on board the research vessel and continuously monitored aerosol and cloud layers up to a height of 30 km. During our mission, we expected to observe a thin residual volcanic aerosol layer in the stratosphere, originating from the Raikoke volcanic eruption in June 2019, with an aerosol optical thickness (AOT) of 0.005–0.01 at 500 nm over the North Pole area during the winter season. However, the highlight of our measurements was the detection of a persistent, 10 km deep aerosol layer in the upper troposphere and lower stratosphere (UTLS), from about 7–8 to 17–18 km height, with clear and unambiguous wildfire smoke signatures up to 12 km and an order of magnitude higher AOT of around 0.1 in the autumn of 2019. Case studies are presented to explain the specific optical fingerprints of aged wildfire smoke in detail. The pronounced aerosol layer was present throughout the winter half-year until the strong polar vortex began to collapse in late April 2020. We hypothesize that the detected smoke originated from extraordinarily intense and long-lasting wildfires in central and eastern Siberia in July and August 2019 and may have reached the tropopause layer by the self-lifting process. In this article, we summarize the main findings of our 7-month smoke observations and characterize the aerosol in terms of geometrical, optical, and microphysical properties. The UTLS AOT at 532 nm ranged from 0.05–0.12 in October–November 2019 and 0.03–0.06 during the main winter season. The Raikoke aerosol fraction was estimated to always be lower than 15 %. We assume that the volcanic aerosol was above the smoke layer (above 13 km height). As an unambiguous sign of the dominance of smoke in the main aerosol layer from 7–13 km height, the particle extinction-to-backscatter ratio (lidar ratio) at 355 nm was found to be much lower than at 532 nm, with mean values of 55 and 85 sr, respectively. The 355–532 nm Ångström exponent of around 0.65 also clearly indicated the presence of smoke aerosol. For the first time, we show a distinct view of the aerosol layering features in the High Arctic from the surface up to 30 km height during the winter half-year. Finally, we provide a vertically resolved view on the late winter and early spring conditions regarding ozone depletion, smoke occurrence, and polar stratospheric cloud formation. The latter will largely stimulate research on a potential impact of the unexpected stratospheric aerosol perturbation on the record-breaking ozone depletion in the Arctic in spring 2020.

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“…The mean rate of temporal ozone change on different fixed isentropic 170 levels from 350 K to 675 K has been calculated from the ozonesonde volume mixing ratio time series by linear regression method. The diabatic cooling/heating rates were calculated by the radiation transfer model (Chou et al, 1999) using daily temperature profiles from JRA reanalysis. A decrease of total column ozone due to chemical ozone loss can be deduced by integrating of cumulative ozone loss profile (Fig.…”

Section: Ozonesonde Analysismentioning

confidence: 99%

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Smyshlyaev

2021

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The features of dynamical processes and changes in the ozone layer in the Arctic stratosphere during the winterspring season 2019-2020 are analyzed using ozonesondes, reanalysis data and numerical experiments with a chemistrytransport model (CTM). Using the trajectory model of the Central Aerological Observatory (TRACAO) and the ERA5 10 reanalysis ozone mixing ratio data, a comparative analysis of the evolution of stratospheric ozone averaged along the trajectories in the winter-spring seasons of 2010-2011, 2015-2016, and 2019-2020 was carried out, which demonstrated that the largest ozone loss at altitudes of 18-20 km within stratospheric polar vortex in the Arctic in winter-spring 2019-2020 exceeded the corresponding values of the other two winter-spring seasons 2010-2011 and 2015-2016 with the largest decrease in ozone content in recent year. The total decrease in the column ozone inside the stratospheric polar vortex, 15 calculated using the vertical ozone profiles obtained based on the ozonesondes data, in the 2019-2020 winter-spring season was more than 150 Dobson Units, which repeated the record depletion for the 2010-2011 winter-spring season. At the same time, the maximum ozone loss in winter 2019-2020 was observed at lower levels than in 2010-2011, which is consistent with the results of trajectory analysis and the results of other authors. The results of numerical calculations with the CTM with dynamical parameters specified from the MERRA-2 reanalysis data, carried out according to several scenarios of accounting 20 for the chemical destruction of ozone, indicated that both dynamical and chemical processes make contributions to ozone loss inside the polar vortex. In this case, dynamical processes predominate in the western hemisphere, while in the eastern hemisphere chemical processes make an almost equal contribution with dynamical factors, and the chemical depletion of ozone is determined not only by heterogeneous processes on the surface of the polar stratospheric clouds, but by the gasphase destruction in nitrogen catalytic cycles as well. 25 of the stratosphere and upper atmosphere (Funke et al., 2016;Pedatella et al., 2018) and ozone layer (Smyshlyaev et al., 30 2016; WMO, 2018). Due to the stronger wave activity and the frequent occurrence of Sudden Stratospheric Warming (SSW), and, consequently, the less stable and warm stratospheric polar vortex, significant ozone anomalies are observed in the Arctic less often than in the Antarctic, where the main SSW was observed only in September 2002 (Solomon, 2014).However, Antarctica has also experienced strong interannual variability in recent years. Thus, in 2015, the ozone anomaly in Antarctica was one of the most significant for all observation years (Vargin et al., 2020a), while in 2019 it was one of the 35

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Dynamical and chemical processes contributing to ozone loss in exceptional Arctic stratosphere winter-spring of 2020

Cited by 11 publications

References 5 publications

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

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

The unexpected smoke layer in the High Arctic winter stratosphere during MOSAiC 2019–2020

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