Dynamics of the Arctic polar vortex during the 1984/1985 sudden stratospheric warming

Abstract. Stratospheric circulation is a critical part of the Arctic ozone cycle. Sudden stratospheric warming events (SSWs) manifest the strongest alteration of stratospheric dynamics. Changes in planetary wave propagation vigorously influence zonal mean zonal wind, temperature, and tracer concentrations in the stratosphere over the high latitudes. In this study, we examine six major SSWs from 2004 to 2020 using the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2). Using the unique density of observations around the Greenland sector at high latitudes, we perform comprehensive comparisons of high latitude observations with the MERRA-2 ozone dataset during the six major SSWs. Our results show that MERRA-2 captures the high variability of mid stratospheric ozone fluctuations during SSWs over high latitudes. However, larger uncertainties are observed in the lower stratosphere and troposphere. The zonally averaged stratospheric ozone shows a dramatic increase of 9–29 % in total column ozone (TCO) near the time of each SSW, which lasts up to two months. The SSWs exhibit a more significant impact on ozone over high northern latitudes when the polar vortex is mostly elongated as seen in 2009 and 2018 compared to the events in which the polar vortex is displaced towards Europe. The regional impact of SSWs over Greenland has a similar structure as the zonal average, however, exhibits more intense ozone anomalies which is reflected by 15–37 % increase in TCO. The influence of SSW on mid stratospheric ozone levels persists longer than their impact on temperature. This paper is focused on the increased (suppressed) wave activity before (after) the SSWs and their impact on ozone variability at high latitudes. This includes an investigation of the different terms of tracer continuity using MERRA-2 parameters, which emphasizes the key role of vertical advection on mid-stratospheric ozone during the SSWs.

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Winter 2018 major sudden stratospheric warming impact on midlatitude mesosphere from microwave radiometer measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-10303-2019 ◽

2019 ◽

Vol 19 (15) ◽

pp. 10303-10317 ◽

Cited By ~ 5

Author(s):

Yuke Wang ◽

Valerii Shulga ◽

Gennadi Milinevsky ◽

Aleksey Patoka ◽

Oleksandr Evtushevsky ◽

...

Keyword(s):

Zonal Wind ◽

Microwave Radiometer ◽

Polar Vortex ◽

The Arctic ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Time Data ◽

Easterly Wind ◽

The Impact ◽

Midlatitude Mesosphere

Abstract. The impact of a major sudden stratospheric warming (SSW) in the Arctic in February 2018 on the midlatitude mesosphere is investigated by performing the microwave radiometer measurements of carbon monoxide (CO) and zonal wind above Kharkiv, Ukraine (50.0∘ N, 36.3∘ E). The mesospheric peculiarities of this SSW event were observed using a recently designed and installed microwave radiometer in eastern Europe for the first time. Data from the ERA-Interim and MERRA-2 reanalyses, as well as the Aura microwave limb sounder measurements, are also used. Microwave observations of the daily CO profiles in January–March 2018 allowed for the retrieval of mesospheric zonal wind at 70–85 km (below the winter mesopause) over the Kharkiv site. Reversal of the mesospheric westerly from about 10 m s−1 to an easterly wind of about −10 m s−1 around 10 February was observed. The local microwave observations at our Northern Hemisphere (NH) midlatitude site combined with reanalysis data show wide-ranging daily variability in CO, zonal wind, and temperature in the mesosphere and stratosphere during the SSW of 2018. The observed local CO variability can be explained mainly by horizontal air mass redistribution due to planetary wave activity. Replacement of the CO-rich polar vortex air by CO-poor air of the surrounding area led to a significant mesospheric CO decrease over the station during the SSW and fragmentation of the vortex over the station at the SSW start caused enhanced stratospheric CO at about 30 km. The results of microwave measurements of CO and zonal wind in the midlatitude mesosphere at 70–85 km altitudes, which still are not adequately covered by ground-based observations, are useful for improving our understanding of the SSW impacts in this region.

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Gravity Waves excited during a Minor Sudden Stratospheric Warming

10.5194/acp-2018-228 ◽

2018 ◽

Author(s):

Andreas Dörnbrack ◽

Sonja Gisinger ◽

Natalie Kaifler ◽

Tanja Portele ◽

Martina Bramberger ◽

...

Keyword(s):

Gravity Waves ◽

Polar Vortex ◽

Internal Gravity Waves ◽

The Arctic ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Coherent Wave ◽

Propagating Waves ◽

A Minor ◽

Inertia Gravity Waves

Abstract. An exceptionally deep upper-air sounding launched from Kiruna airport (67.82° N, 20.337° E) on 30 January 2016 stimulated the current investigation of internal gravity waves excited during a minor sudden stratospheric warming (SSW) in the Arctic winter 2015/16. The analysis of the radiosonde profile revealed large kinetic and potential energies in the upper stratosphere without any simultaneous enhancement of upper tropospheric and lower stratospheric values. Upward propagating inertia-gravity waves in the upper stratosphere and downward propagating modes in the lower stratosphere indicated a region of gravity wave generation in the stratosphere. Two-dimensional wavelet analysis was applied to vertical time series of temperature fluctuations in order to determine the vertical propagation direction of the stratospheric gravity waves in one-hourly high-resolution meteorological analyses and short-term forecasts. The separation of up- and downward propagating waves provided further evidence for a stratospheric source of gravity waves. The scale-dependent decomposition of the flow into a balanced component and inertia-gravity waves showed that coherent wave packets preferentially occurred at the inner edge of the Arctic polar vortex where a sub-vortex formed during the minor SSW.

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Analysis of the Arctic polar vortex dynamics during the sudden stratospheric warming in January 2009

Arctic and Antarctic Research ◽

10.30758/0555-2648-2021-67-2-134-146 ◽

2021 ◽

Vol 67 (2) ◽

pp. 134-146

Author(s):

V. V. Zuev ◽

E. S. Savelieva ◽

A. V. Pavlinsky

Keyword(s):

Wind Speed ◽

Polar Vortex ◽

Reanalysis Data ◽

Wave Activity ◽

The Arctic ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Mean Wind Speed ◽

The Mean ◽

Middle Stratosphere

The Arctic polar vortex is often affected by wave activity during its life cycle. The planetary Rossby waves propagating from the troposphere to the stratosphere occasionally lead to the displacement or splitting of the polar vortex, accompanied by sudden stratospheric warming (SSW). In January 2009, one of the largest SSWs was observed in the Arctic. In this work, the dynamics of the polar vortex during the 2009 SSW is considered using a new method that allows one to estimate the vortex area, the wind speed at the vortex edge, the mean temperature and ozone mass mixing ratio inside the vortex, based on the fact that the Arctic vortex edge at the 50 and 10 hPa pressure levels is determined by the geopotential values, respectively, 19.5. 104 and 29.5. 104 m2 /s2 , using the ERA5 reanalysis data. The application of this method is justified for the Arctic polar vortex, which is characterized by significant variability, especially during the period of its splitting. The splitting of the polar vortex in 2009 was observed on January 24 and 28, respectively, in the middle and lower stratosphere. About a week after the splitting, the vortices became closer in characteristics to small cyclones, which completely collapsed within 1–3 weeks. The influence of planetary wave activity on the polar vortex does not always lead to its breakdown. Short-term splitting of the polar vortex is sometimes observed for several days after which the polar vortex strengthens again and PSCs form inside the vortex. Such a recovery of the polar vortex is most likely to occur in the winter. Based on the analysis of the dynamics of the Arctic polar vortex for 1979–2020 and using the example of the 2009 SSW, we showed that when the vortex area decreases to less than 10 million km2 and the mean wind speed at the vortex edge decreases below 30 and 45 m/s, respectively, in the lower and middle stratosphere, the polar vortex becomes a small cyclone (with significantly higher temperatures within it), which usually collapses within 3 weeks.

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Gravity waves excited during a minor sudden stratospheric warming

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-12915-2018 ◽

2018 ◽

Vol 18 (17) ◽

pp. 12915-12931 ◽

Cited By ~ 10

Author(s):

Andreas Dörnbrack ◽

Sonja Gisinger ◽

Natalie Kaifler ◽

Tanja Christina Portele ◽

Martina Bramberger ◽

...

Keyword(s):

Gravity Waves ◽

Polar Vortex ◽

Internal Gravity Waves ◽

The Arctic ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Coherent Wave ◽

Propagating Waves ◽

A Minor ◽

Inertia Gravity Waves

Abstract. An exceptionally deep upper-air sounding launched from Kiruna airport (67.82∘ N, 20.33∘ E) on 30 January 2016 stimulated the current investigation of internal gravity waves excited during a minor sudden stratospheric warming (SSW) in the Arctic winter 2015/16. The analysis of the radiosonde profile revealed large kinetic and potential energies in the upper stratosphere without any simultaneous enhancement of upper tropospheric and lower stratospheric values. Upward-propagating inertia-gravity waves in the upper stratosphere and downward-propagating modes in the lower stratosphere indicated a region of gravity wave generation in the stratosphere. Two-dimensional wavelet analysis was applied to vertical time series of temperature fluctuations in order to determine the vertical propagation direction of the stratospheric gravity waves in 1-hourly high-resolution meteorological analyses and short-term forecasts. The separation of upward- and downward-propagating waves provided further evidence for a stratospheric source of gravity waves. The scale-dependent decomposition of the flow into a balanced component and inertia-gravity waves showed that coherent wave packets preferentially occurred at the inner edge of the Arctic polar vortex where a sub-vortex formed during the minor SSW.

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Tropospheric forcing of the boreal polar vortex splitting in January 2003

Annales Geophysicae ◽

10.5194/angeo-28-2133-2010 ◽

2010 ◽

Vol 28 (11) ◽

pp. 2133-2148 ◽

Cited By ~ 9

Author(s):

D. H. W. Peters ◽

P. Vargin ◽

A. Gabriel ◽

N. Tsvetkova ◽

V. Yushkov

Keyword(s):

Rossby Wave ◽

Planetary Wave ◽

Winter Season ◽

Polar Vortex ◽

Wave Activity ◽

The Arctic ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Stratospheric Polar Vortex ◽

Wave Trains

Abstract. The dynamical evolution of the relatively warm stratospheric winter season 2002–2003 in the Northern Hemisphere was studied and compared with the cold winter 2004–2005 based on NCEP-Reanalyses. Record low temperatures were observed in the lower and middle stratosphere over the Arctic region only at the beginning of the 2002–2003 winter. Six sudden stratospheric warming events, including the major warming event with a splitting of the polar vortex in mid-January 2003, have been identified. This led to a very high vacillation of the zonal mean circulation and a weakening of the stratospheric polar vortex over the whole winter season. An estimate of the mean chemical ozone destruction inside the polar vortex showed a total ozone loss of about 45 DU in winter 2002–2003; that is about 2.5 times smaller than in winter 2004–2005. Embedded in a winter with high wave activity, we found two subtropical Rossby wave trains in the troposphere before the major sudden stratospheric warming event in January 2003. These Rossby waves propagated north-eastwards and maintained two upper tropospheric anticyclones. At the same time, the amplification of an upward propagating planetary wave 2 in the upper troposphere and lower stratosphere was observed, which could be caused primarily by those two wave trains. Furthermore, two extratropical Rossby wave trains over the North Pacific Ocean and North America were identified a couple of days later, which contribute mainly to the vertical planetary wave activity flux just before and during the major warming event. It is shown that these different tropospheric forcing processes caused the major warming event and contributed to the splitting of the polar vortex.

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Winter 2018 major sudden stratospheric warming impact on midlatitude mesosphere from microwave radiometer measurements

10.5194/acp-2018-1361 ◽

2019 ◽

Cited By ~ 2

Author(s):

Yuke Wang ◽

Valery Shulga ◽

Gennadi Milinevsky ◽

Aleksey Patoka ◽

Oleksandr Evtushevsky ◽

...

Keyword(s):

Zonal Wind ◽

Geopotential Height ◽

Microwave Radiometer ◽

Recovery Phase ◽

The Arctic ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Easterly Wind ◽

The Impact ◽

Midlatitude Mesosphere

Abstract. The impact of a major sudden stratospheric warming (SSW) in the Arctic in February 2018 on the mid-latitude mesosphere was investigated by performing microwave radiometer measurements of carbon monoxide (CO) and zonal wind above Kharkiv, Ukraine (50.0° N, 36.3° E). The mesospheric peculiarities of this SSW event were observed using recently designed and installed microwave radiometer in East Europe for the first time. The data from the ERA-Interim and NCEP–NCAR reanalyses, as well as the Aura Microwave Limb Sounder measurements, have been also used. Microwave observations of the daily CO profiles in January–March 2018 allowed retrieving mesospheric zonal wind at 70–85 km (below the winter mesopause) over the Kharkiv site. The reverse of the mesospheric westerly from about 10 m s−1 to the easterly wind of about −10 m s−1 around 10 February has been registered. Local microwave observations in the NH midlatitudes combined with reanalysis data show wide ranges of daily variability in CO, zonal wind, temperature and geopotential height in the mesosphere and stratosphere during the SSW 2018. Oscillations in the vertical CO profile, zonal wind, and geopotential height during the SSW, stratopause disappearance after the SSW onset and strong CO and westerly wind peaks at the start of the SSW recovery phase have been observed. The observed CO variability can be explained by vertical and horizontal air mass redistribution due to planetary wave activity with the replacement of the CO-rich air by CO-poor air and vice versa, in agreement with other studies. The results of microwave measurements of CO and zonal wind in the midlatitude mesosphere at 70–85 km altitudes, which still is not adequately covered by ground-based observations, are useful for improving our understanding of the SSW impacts in this region.

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Stratosphere-troposphere Dynamical Coupling over Boreal Extratropics during the Sudden Stratospheric Warming in the Arctic in January–February 2017

Russian Meteorology and Hydrology ◽

10.3103/s1068373918050011 ◽

2018 ◽

Vol 43 (5) ◽

pp. 277-287 ◽

Cited By ~ 2

Author(s):

P. N. Vargin

Keyword(s):

The Arctic ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Dynamical Coupling

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Polar processing in a split vortex: early winter Arctic ozone loss in 2012/13

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-4973-2015 ◽

2015 ◽

Vol 15 (4) ◽

pp. 4973-5029 ◽

Cited By ~ 3

Author(s):

G. L. Manney ◽

Z. D. Lawrence ◽

M. L. Santee ◽

N. J. Livesey ◽

A. Lambert ◽

...

Keyword(s):

Nitric Acid ◽

Lower Stratosphere ◽

Polar Vortex ◽

The Arctic ◽

Early Winter ◽

Sudden Stratospheric Warming ◽

Ozone Loss ◽

Chlorine Monoxide ◽

Polar Stratospheric Cloud ◽

Vortex Split

Abstract. A sudden stratospheric warming (SSW) in early January 2013 caused the polar vortex to split. After the lower stratospheric vortex split on 8 January, the two offspring vortices – one over Canada and the other over Siberia – remained intact, well-confined, and largely at latitudes that received sunlight until they reunited at the end of January. As the SSW began, temperatures abruptly rose above chlorine activation thresholds throughout the lower stratosphere. The vortex was very disturbed prior to the SSW, and was exposed to much more sunlight than usual in December 2012 and January 2013. Aura Microwave Limb Sounder (MLS) nitric acid (HNO3) data and observations from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) indicate extensive polar stratospheric cloud (PSC) activity, with evidence of PSCs containing solid nitric acid trihydrate particles during much of December 2012. Consistent with the sunlight exposure and PSC activity, MLS observations show that chlorine monoxide (ClO) became enhanced early in December. Despite the cessation of PSC activity with the onset of the SSW, enhanced vortex ClO persisted until mid-February, indicating lingering chlorine activation. The smaller Canadian offspring vortex had lower temperatures, lower HNO3, lower hydrogen chloride (HCl), and higher ClO in late January than the Siberian vortex. Chlorine deactivation began later in the Canadian than in the Siberian vortex. HNO3 remained depressed within the vortices after temperatures rose above the PSC existence threshold, and passive transport calculations indicate vortex-averaged denitrification of about 4 ppbv; the resulting low HNO3 values persisted until the vortex dissipated in mid-February. Consistent with the strong chlorine activation and exposure to sunlight, MLS measurements show rapid ozone loss commencing in mid-December and continuing through January. Lagrangian transport estimates suggest ~ 0.7–0.8 ppmv (parts per million by volume) vortex-averaged chemical ozone loss by late January near 500 K (~ 21 km), with substantial loss occurring from ~ 450 to 550 K. The surface area of PSCs in December 2012 was larger than that in any other December observed by CALIPSO. As a result of denitrification, HNO3 abundances in 2012/13 were among the lowest in the MLS record for the Arctic. ClO enhancement was much greater in December 2012 through mid-January 2013 than that at the corresponding time in any other Arctic winter observed by MLS. Furthermore, reformation of HCl appeared to play a greater role in chlorine deactivation than in more typical Arctic winters. Ozone loss in December 2012 and January 2013 was larger than any previously observed in those months. This pattern of exceptional early winter polar processing and ozone loss resulted from the unique combination of dynamical conditions associated with the early January 2013 SSW, namely unusually low temperatures in December 2012 and offspring vortices that remained well-confined and largely in sunlit regions for about a month after the vortex split.

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The Role of Zonal Asymmetry in the Enhancement and Suppression of Sudden Stratospheric Warming Variability by the Madden–Julian Oscillation

Journal of Climate ◽

10.1175/jcli-d-17-0489.1 ◽

2018 ◽

Vol 31 (6) ◽

pp. 2399-2415 ◽

Cited By ~ 4

Author(s):

Wanying Kang ◽

Eli Tziperman

Keyword(s):

General Circulation ◽

Dominant Role ◽

The Arctic ◽

Stationary Waves ◽

Madden Julian Oscillation ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Zonal Asymmetry ◽

Forced Waves ◽

The Arctic Oscillation

Sudden stratospheric warming (SSW) events influence the Arctic Oscillation and midlatitude extreme weather. Previous work showed the Arctic stratosphere to be influenced by the Madden–Julian oscillation (MJO) and that the SSW frequency increases with an increase of the MJO amplitude, expected in a warmer climate. It is shown here that the zonal asymmetry in both the background state and forcing plays a dominant role, leading to either enhancement or suppression of SSW events by MJO-like forcing. When applying a circumglobal MJO-like forcing in a dry dynamic core model, the MJO-forced waves can change the general circulation in three ways that affect the total vertical Eliassen–Palm flux in the Arctic stratosphere. First, weakening the zonal asymmetry of the tropospheric midlatitude jet, and therefore preventing the MJO-forced waves from propagating past the jet. Second, weakening the jet amplitude, reducing the waves generated in the midlatitudes, especially stationary waves, and therefore the upward-propagating planetary waves. Third, reducing the Arctic lower-stratospheric refractory index, which prevents waves from upward propagation. These effects stabilize the Arctic vortex and lower the SSW frequency. The longitudinal range to which the MJO-like forcing is limited plays an important role as well, and the strongest SSW frequency increase is seen when the MJO is located where it is observed in current climate. The SSW suppression effects are active when the MJO-like forcing is placed at different longitudinal locations. This study suggests that future trends in both the MJO amplitude and its longitudinal extent are important for predicting the Arctic stratosphere response.

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