scholarly journals The Remarkably Strong Arctic Stratospheric Polar Vortex of Winter 2020: Links to Record‐Breaking Arctic Oscillation and Ozone Loss

2020 ◽  
Vol 125 (22) ◽  
Author(s):  
Zachary D. Lawrence ◽  
Judith Perlwitz ◽  
Amy H. Butler ◽  
Gloria L. Manney ◽  
Paul A. Newman ◽  
...  
Keyword(s):  
Arctic Oscillation ◽  
Polar Vortex ◽  
Stratospheric Polar Vortex ◽  
Ozone Loss

scholarly journals The Remarkably Strong Arctic Stratospheric Polar Vortex of Winter 2020: Links to Record-Breaking Arctic Oscillation and Ozone Loss

2020 ◽  
Author(s):  
Zachary Duane Lawrence ◽  
Judith Perlwitz ◽  
Amy Hawes Butler ◽  
Gloria L Manney ◽  
Paul A. Newman ◽  
...  
Keyword(s):  
Arctic Oscillation ◽  
Polar Vortex ◽  
Stratospheric Polar Vortex ◽  
Ozone Loss

Improvement in Prediction of the Arctic Oscillation with a Realistic Ocean Initial Condition in a CGCM

2015 ◽  
Vol 28 (22) ◽  
pp. 8951-8967 ◽  
Author(s):  
Hae-Jeong Kim ◽  
Joong-Bae Ahn
Keyword(s):  
Arctic Oscillation ◽  
Polar Vortex ◽  
Polar Front ◽  
Forecast Skill ◽  
Sea Surface ◽  
The Arctic ◽  
Initial Condition ◽  
Stratospheric Polar Vortex ◽  
The Arctic Oscillation ◽  
Polar Front Jet

Abstract This study verifies the impact of improved ocean initial conditions on the Arctic Oscillation (AO) forecast skill by assessing the one-month lead predictability of boreal winter AO using the Pusan National University (PNU) coupled general circulation model (CGCM). Hindcast experiments were performed on two versions of the model, one does not use assimilated ocean initial data (V1.0) and one does (V1.1), and the results were comparatively analyzed. The forecast skill of V1.1 was superior to that of V1.0 in terms of the correlation coefficient between the predicted and observed AO indices. In the regression analysis, V1.1 showed more realistic spatial similarities than V1.0 did in predicted sea surface temperature and atmospheric circulation fields. The authors suggest the relative importance of the contribution of the ocean initial condition to the AO forecast skill was because the ocean data assimilation increased the predictability of the AO, to some extent, through the improved interaction between tropical forcing induced by realistic sea surface temperature (SST) and atmospheric circulation. In V1.1, as in the observation, the cold equatorial Pacific SST anomalies generated the weakened tropical convection and Hadley circulation over the Pacific, resulting in a decelerated subtropical jet and accelerated polar front jet in the extratropics. The intensified polar front jet implies a stronger stratospheric polar vortex relevant to the positive AO phase; hence, surface manifestations of the reflected positive AO phase were then induced through the downward propagation of the stratospheric polar vortex. The results suggest that properly assimilated initial ocean conditions might contribute to improve the predictability of global oscillations, such as the AO, through large-scale tropical ocean–atmosphere interaction.

The stratospheric polar vortex and sub-vortex : fluid dynamics and midlatitude ozone loss

1995 ◽  
Vol 352 (1699) ◽  
pp. 227-240 ◽  
Keyword(s):  
Lower Stratosphere ◽  
Flow Reactor ◽  
Polar Vortex ◽  
Large Mass ◽  
Heterogeneous Reactions ◽  
Stratospheric Polar Vortex ◽  
Ozone Loss ◽  
Middle Latitudes ◽  
Polar Stratospheric Cloud ◽  
Flow Through

It has been suggested on the basis of certain chemical observations that the wintertime stratospheric polar vortex might act as a chemical processor, or flow reactor, through which large amounts of air - of the order of one vortex mass per month or three vortex masses per winter - flow downwards and then outwards to middle latitudes in the lower stratosphere. If such a flow were to exist, then most of the air involved would become chemically ‘activated’, or primed for ozone destruction, while passing through the low temperatures of the vortex where fast heterogeneous reactions can take place on polar-stratospheric-cloud particles. There could be serious implications for our understanding of ozone-hole chemistry and for midlatitude ozone loss, both in the Northern and in the Southern Hemisphere. This paper will briefly assess current fluid-dynamical thinking about flow through the vortex. It is concluded that the vortex typically cannot sustain an average throughput much greater than about a sixth of a vortex mass per month, or half a vortex mass per winter, unless a large and hitherto unknown mean circumferential force acts persistently on the vortex in an eastward or ‘spin-up’ sense, prograde with the Earth’s rotation. By contrast, the ‘sub-vortex’ below pressure-altitudes of about 70 hPa (more precisely, on isentropic surfaces below potential temperatures of about 400 K) is capable of relatively large mass throughput depending, however, on tropospheric weather beneath, concerning which observational data are sparse.

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

2021 ◽  
Author(s):  
Sergei P. Smyshlyaev ◽  
Pavel N. Vargin ◽  
Alexander N. Lukyanov ◽  
Natalia D. Tsvetkova ◽  
Maxim A. Motsakov
Keyword(s):  
Polar Vortex ◽  
Reanalysis Data ◽  
Chemical Processes ◽  
Western Hemisphere ◽  
The Arctic ◽  
Spring Season ◽  
Dynamical Processes ◽  
Stratospheric Polar Vortex ◽  
Ozone Loss ◽  
Eastern Hemisphere

Abstract. The features of dynamical processes and changes in the ozone layer in the Arctic stratosphere during the winter-spring season 2019–2020 are analyzed using ozonesondes, reanalysis data and numerical experiments with a chemistry-transport model (CTM). Using the trajectory model of the Central Aerological Observatory (TRACAO) and the ERA5 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, 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 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 gas-phase destruction in nitrogen catalytic cycles as well.

scholarly journals Polar processing in a split vortex: Arctic ozone loss in early winter 2012/2013

2015 ◽  
Vol 15 (10) ◽  
pp. 5381-5403 ◽  
Author(s):  
G. L. Manney ◽  
Z. D. Lawrence ◽  
M. L. Santee ◽  
N. J. Livesey ◽  
A. Lambert ◽  
...  
Keyword(s):  
Polar Vortex ◽  
Sunlight Exposure ◽  
The Arctic ◽  
Stratospheric Polar Vortex ◽  
Ozone Loss ◽  
Chlorine Monoxide ◽  
Polar Stratospheric Cloud ◽  
Gas Measurements ◽  
Time Of Year ◽  
The One

Abstract. A sudden stratospheric warming (SSW) in early January 2013 caused the Arctic polar vortex to split and temperatures to rapidly rise above the threshold for chlorine activation. However, ozone in the lower stratospheric polar vortex from late December 2012 through early February 2013 reached the lowest values on record for that time of year. Analysis of Aura Microwave Limb Sounder (MLS) trace gas measurements and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) polar stratospheric cloud (PSC) data shows that exceptional chemical ozone loss early in the 2012/13 Arctic winter resulted from a unique combination of meteorological conditions associated with the early-January 2013 SSW: unusually low temperatures in December 2012, offspring vortices within which air remained well isolated for nearly 1 month after the vortex split, and greater-than-usual vortex sunlight exposure throughout December 2012 and January 2013. Conditions in the two offspring vortices differed substantially, with the one overlying Canada having lower temperatures, lower nitric acid (HNO3), lower hydrogen chloride, more sunlight exposure/higher ClO in late January, and a later onset of chlorine deactivation than the one overlying Siberia. MLS HNO3 and CALIPSO data indicate that PSC activity in December 2012 was more extensive and persistent than at that time in any other Arctic winter in the past decade. Chlorine monoxide (ClO, measured by MLS) rose earlier than previously observed and was the largest on record through mid-January 2013. Enhanced vortex ClO persisted until mid-February despite the cessation of PSC activity when the SSW started. Vortex HNO3 remained depressed after PSCs had disappeared; passive transport calculations indicate vortex-averaged denitrification of about 4 parts per billion by volume. The estimated vortex-averaged chemical ozone loss, ~ 0.7–0.8 parts per million by volume near 500 K (~21 km), was the largest December/January loss in the MLS record from 2004/05 to 2014/15.

High vs. low latitude influence on seasonal stratospheric pathways in the atmospheric model ICON

2021 ◽  
Author(s):  
Raphael Köhler ◽  
Dörthe Handorf ◽  
Ralf Jaiser ◽  
Klaus Dethloff
Keyword(s):  
Large Scale ◽  
Arctic Oscillation ◽  
Southern Oscillation ◽  
Polar Vortex ◽  
Atmospheric Model ◽  
The Arctic ◽  
Late Winter ◽  
Stratospheric Polar Vortex ◽  
Enso Events ◽  
Hemisphere Winter

<p>Stratospheric pathways play an important role in connecting distant anomaly patterns to each other on seasonal timescales. As long-lived stratospheric extreme events can influence the large-scale tropospheric circulation on timescales of multiple weeks, stratospheric pathways have been identified as one of the main potential sources for subseasonal to seasonal predictability in mid-latitudes. These pathways have been shown to connect Arctic anomalies to lower latitudes and vice versa. However, there is an ongoing discussion on how strong these stratospheric pathways are and how they exactly work.</p><p> </p><p>In this context, we investigate two strongly discussed stratospheric pathways by analysing a suite of seasonal experiments with the atmospheric model ICON: On the one hand, the effect of El Niño-Southern Oscillation (ENSO) on the stratospheric polar vortex, and thus the circulation in mid and high latitudes in winter. And on the other hand, the effect of a rapidly changing Arctic on lower latitudes via the stratosphere. The former effect is simulated realistically by ICON, and the results from the ensemble simulations suggest that ENSO has an effect on the large-scale Northern Hemisphere winter circulation. The ICON experiments and the reanalysis exhibit a weakened stratospheric vortex in warm ENSO years. Furthermore, in particular in winter, warm ENSO events favour the negative phase of the Arctic Oscillation, whereas cold events favour the positive phase. The ICON simulations also suggest a significant effect of ENSO on the Atlantic-European sector in late winter. Unlike the effect of ENSO, ICON simulations and the reanalysis do not agree on the stratospheric pathway for Arctic-midlatitude linkages. Whereas the reanalysis exhibits a weakening of the stratospheric vortex in midwinter and a connected tropospheric negative Arctic Oscillation circulation response to amplified Arctic warming, this is not the case in the ICON simulations. Implications and potential reasons for this discrepancy are further analysed and discussed in this work.  </p>

scholarly journals A strong phase reversal of the Arctic Oscillation in midwinter 2015/2016: Role of the stratospheric polar vortex and tropospheric blocking

2016 ◽  
Vol 121 (22) ◽  
pp. 13,443-13,457 ◽  
Author(s):  
Hoffman H. N. Cheung ◽  
Wen Zhou ◽  
Marco Y. T. Leung ◽  
C. M. Shun ◽  
S. M. Lee ◽  
...  
Keyword(s):  
Arctic Oscillation ◽  
Polar Vortex ◽  
The Arctic ◽  
Stratospheric Polar Vortex ◽  
Strong Phase ◽  
Phase Reversal ◽  
The Arctic Oscillation

scholarly journals Diversity of the Wintertime Arctic Oscillation Pattern among CMIP5 Models: Role of the Stratospheric Polar Vortex

2019 ◽  
Vol 32 (16) ◽  
pp. 5235-5250 ◽  
Author(s):  
Hainan Gong ◽  
Lin Wang ◽  
Wen Chen ◽  
Renguang Wu ◽  
Wen Zhou ◽  
...  
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Arctic Oscillation ◽  
Climate Models ◽  
Polar Vortex ◽  
Cmip5 Models ◽  
Stratospheric Polar Vortex ◽  
The North ◽  
The North Atlantic ◽  
The North Pacific

AbstractThe wintertime Arctic Oscillation (AO) pattern in phase 5 of the Coupled Model Intercomparison Project (CMIP5) climate models displays notable differences from the reanalysis. The North Pacific center of the AO pattern is larger in the ensemble mean of 27 models than in the reanalysis, and the magnitude of the North Pacific center of the AO pattern varies largely among the models. This study investigates the plausible sources of the diversity of the AO pattern in the models. Analysis indicates that the amplitude of the North Pacific center is associated with the coupling between the North Pacific and North Atlantic, which in turn is primarily modulated by the strength of the stratospheric polar vortex. A comparative analysis is conducted for the strong polar vortex (SPV) and weak polar vortex (WPV) models. It reveals that a stronger stratospheric polar vortex induces more planetary waves to reflect from the North Pacific to the North Atlantic and more wave activity fluxes to propagate from the North Pacific to the North Atlantic in the SPV models than in the WPV models. Thus, the coupling of atmospheric circulation between the North Pacific and North Atlantic is stronger in the SPV models, which facilitates more North Pacific variability to be involved in the AO variability and induces a stronger North Pacific center in the AO pattern. The increase in vertical resolution may improve the simulation of the stratospheric polar vortex and thereby reduces the model biases in the North Pacific–North Atlantic coupling and thereby the amplitude of the North Pacific center of the AO pattern in models.

scholarly journals Arctic Oscillation impact on thermal regime in the Eastern part of the Baltic region

2016 ◽  
Vol 2 (1) ◽  
pp. 89-96
Author(s):  
Индре Гечайте ◽  
Indre Gecaite ◽  
Александр Погорельцев ◽  
Aleksandr Pogoreltsev ◽  
Александр Угрюмов ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Geomagnetic Activity ◽  
Large Scale ◽  
Arctic Oscillation ◽  
Polar Vortex ◽  
Baltic Region ◽  
Stratospheric Polar Vortex ◽  
Weather Forecasts ◽  
Tropospheric Circulation ◽  
The Baltic

The paper presents statistical estimations of Arctic Oscillation (AO) impact on air temperature regime in the eastern part of the Baltic region. The region is characterized by high inter-annual and inter-seasonal variability. It is important to note that in the region of global warming extremely low winter temperatures can be observed on the European territory of Russia. AO is one of the large-scale global patterns of atmospheric circulation closely associated with weather variability in northern Europe. AО anomalies occur in the upper atmosphere (stratosphere) and only then are transferred to tropospheric lower layers. The anomalies can persist over a long period of time (up to two months); so they can serve as precursors in long-range weather forecasts. In turn, changes in stratospheric polar vortex and sudden stratospheric warmings can be related to geomagnetic activity. Perhaps geomagnetic activity influences the meridional temperature gradient and then changes the structure of the stratospheric zonal wind. These changes have an effect on the tropospheric circulation. The stratosphere–troposphere coupling takes place during winter months. Therefore, the paper deals with extremely cold winter anomalies in the eastern part of the Baltic Sea region. At the same time, we examine atmospheric circulation peculiarities associated with AO phase change. We analyze data for 1951–2014.

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