scholarly journals Gravity Waves excited during a Minor Sudden Stratospheric Warming

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.

scholarly journals Gravity waves excited during a minor sudden stratospheric warming

2018 ◽  
Vol 18 (17) ◽  
pp. 12915-12931 ◽  
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.

scholarly journals Analyzing ozone variations and uncertainties at high latitudes during Sudden Stratospheric Warming events using MERRA-2

2021 ◽  
Author(s):  
Shima Bahramvash Shams ◽  
Von P. Walden ◽  
James W. Hannigan ◽  
William J. Randel ◽  
Irina V. Petropavlovskikh ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Polar Vortex ◽  
The Arctic ◽  
High Latitudes ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Total Column Ozone ◽  
Northern Latitudes ◽  
Stratospheric Dynamics ◽  
Zonal Average

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.

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

2019 ◽  
Vol 19 (15) ◽  
pp. 10303-10317 ◽  
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.

scholarly journals Dynamical evolution of a minor sudden stratospheric warming in the Southern Hemisphere in 2019

2021 ◽  
Author(s):  
Guangyu Liu ◽  
Toshihiko Hirooka ◽  
Nawo Eguchi ◽  
Kirstin Krüger
Keyword(s):  
Southern Hemisphere ◽  
Vertical Component ◽  
Polar Vortex ◽  
Planetary Waves ◽  
High Latitudes ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Zonal Wavenumber ◽  
Westerly Winds ◽  
A Minor

Abstract. This study analyzes the Japanese 55-year Reanalysis (JRA-55) dataset from 2002 to 2019 to examine the sudden stratospheric warming event that occurred in the Southern Hemisphere (SH) in 2019 (hereafter referred to as SSW2019). Strong warming at the polar cap and decelerated westerly winds were observed, but since there was no reversal of westerly winds to easterly winds at 60° S in the middle to lower stratosphere, the SSW2019 is classified as a minor warming event. The results show that quasi-stationary planetary waves of zonal wavenumber 1 developed during the SSW2019. The strong vertical component of the Eliassen–Palm flux with zonal wavenumber 1 is indicative of pronounced propagation of planetary waves to the stratosphere. The wave driving in September 2019 shows that the values are larger than those of the major SSW event in 2002 (hereafter referred to as SSW2002). Since there was no pronounced preconditioning (as in SSW2002) and the polar vortex was already strong before the SSW2019 occurred, a major disturbance of the polar vortex was unlikely to have taken place. The strong wave driving in SSW2019 occurred in high latitudes. Waveguides (i.e., positive values of the refractive index) are found at high latitudes in the upper stratosphere during the warming period, which provided favorable conditions for quasi-stationary planetary waves to propagate upward and poleward.

scholarly journals The sudden stratospheric warming of the Arctic winter 2009/2010: comparison to other recent warm winters

2012 ◽  
Vol 12 (3) ◽  
pp. 7243-7271 ◽  
Author(s):  
J. Kuttippurath ◽  
G. Nikulin
Keyword(s):  
Planetary Wave ◽  
Mean Amplitude ◽  
The Arctic ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Ozone Loss ◽  
Zonal Winds ◽  
The Past ◽  
Large Vortex ◽  
A Minor

Abstract. The Arctic winter 2009/10 was moderately cold in December. A minor warming occurred around mid-December due to a wave 2 amplification split the lower stratospheric vortex into two lobes. The vortices merged again and formed a relatively large vortex in a few days. The temperatures began to rise by mid-January and triggered a major sudden stratospheric warming (SSW) by the reversal of westerlies in late (24–26) January, driven by a planetary wave 1 with a peak amplitude of about 100 m2 s−2 at 60° N/10 hPa. The momentum flux associated with this warming showed the largest value in the recent winters, about 450 m2 s−2 at 60° N/10 hPa. The associated vortex split confined to altitudes below 10 hPa and hence, the major warming (MW) was a vortex displacement event. Large amounts of Eliassen-Palm (EP) and wave 2 EP fluxes (3.9 ×105 kg s−2) are found shortly before the MW event at 100 hPa over 45–75° N, suggesting a tropospheric preconditioning of the MW event. We observe an increase in SSWs in the Arctic in recent years, as there were 6 MWs in 6 out of the 7 winters of 2003/04–2009/10, which confirms the conclusions of previous studies on the SSWs in winters prior to 2003/04. Each MW event was unique as far as its evolution and related polar processes were concerned. As compared to the MWs in the recent Arctic winters, the strongest MW was observed in 2008/09 and was initiated by a wave 2 event. A detailed diagnosis of ozone loss during the past fifteen years shows that the loss is inversely proportional to the intensity and timing of SSWs in each winter, where early MWs lead to minimal loss. The ozone loss shows a good correlation with the zonal mean amplitude of zonal winds in January over 60–90° N, suggesting a proxy for MWs in the Arctic winters.

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

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.

Modeling of the effect of internal gravity waves on upper atmospheric conditions during sudden stratospheric warming

2016 ◽  
Vol 2 (3) ◽  
pp. 99-105 ◽  
Author(s):  
Павел Васильев ◽  
Pavel Vasilyev ◽  
Иван Карпов ◽  
Ivan Karpov ◽  
Сергей Кшевецкий ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Internal Gravity Waves ◽  
Upper Atmosphere ◽  
Stratospheric Warming ◽  
Atmospheric Conditions ◽  
Dimensional Model ◽  
Sudden Stratospheric Warming ◽  
Temperature Changes ◽  
Ionospheric Effects ◽  
Charged Component

We present results of modeling of the effect of internal gravity waves (IGW), excited in the region of development of a sudden stratospheric warming (SSW), on upper atmospheric conditions. In the numerical experiment, we use a two-dimensional model of propagation of atmospheric waves, taking into account dissipative and nonlinear processes accompanying wave propagation. As a source of disturbances we consider temperature and density disturbances in the stratosphere during SSWs. Amplitude and frequency characteristics of the source of disturbances are estimated from observations and IGW theory. Numerical calculations showed that waves generated at stratospheric heights during SSW can cause temperature changes in the upper atmosphere. Maximum relative disturbances, caused by such waves, with respect to quiet conditions are observed at 100–200 km. Disturbances of the upper atmosphere in turn have an effect on the dynamics of charged component in the ionosphere and can contribute to observable ionospheric effects of SSW.

scholarly journals Modeling of the effect of internal gravity waves on upper atmospheric conditions during sudden stratospheric warming

2016 ◽  
Vol 2 (3) ◽  
pp. 69-73
Author(s):  
Павел Васильев ◽  
Pavel Vasilyev ◽  
Иван Карпов ◽  
Ivan Karpov ◽  
Сергей Кшевецкий ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Internal Gravity Waves ◽  
Upper Atmosphere ◽  
Stratospheric Warming ◽  
Atmospheric Conditions ◽  
Dimensional Model ◽  
Sudden Stratospheric Warming ◽  
Temperature Changes ◽  
Ionospheric Effects ◽  
Charged Component

We present results of modeling of the effect of internal gravity waves (IGW), excited in the region of development of a sudden stratospheric warming (SSW), on upper atmospheric conditions. In the numerical experiment, we use a two-dimensional model of propagation of atmospheric waves, taking into account dissipative and nonlinear processes accompanying wave propagation. As a source of disturbances we consider temperature and density disturbances in the stratosphere during SSWs. Amplitude and frequency characteristics of the source of disturbances are estimated from observations and IGW theory. Numerical calculations showed that waves generated at stratospheric heights during SSW can cause temperature changes in the upper atmosphere. Maximum relative disturbances, generated by such waves, with respect to quiet conditions are observed at 100–200 km. Disturbances of the upper atmosphere in turn have an effect on dynamics of a charged component in the ionosphere and can contribute to observable ionospheric effects of SSW.

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