scholarly journals Quasi-Periodic Variations of the Polar Vortex in the Southern Hemisphere Stratosphere Due to Wave–Wave Interaction

2004 ◽  
Vol 61 (21) ◽  
pp. 2510-2527 ◽  
Author(s):  
Yasuko Hio ◽  
Shigeo Yoden
Keyword(s):  
Southern Hemisphere ◽  
Traveling Wave ◽  
Polar Vortex ◽  
Wave Interaction ◽  
Stationary Wave ◽  
Late Winter ◽  
Transient Wave ◽  
Reanalysis Dataset ◽  
Zonal Wavenumber ◽  
Comparable Amplitude

Abstract The winter polar vortex in the Southern Hemisphere stratosphere is characterized by prominent quasi-stationary planetary waves: zonal wavenumber 1 (wave 1) and the eastward-traveling wave (wave 2). Quasi-periodic variations of the polar vortex are investigated in terms of the wave–wave interaction between wave 1 and wave 2 with both the NCEP–NCAR reanalysis dataset from 1979 to 2002 and a spherical barotropic model. A typical case shows that the transient wave 1 generated by the wave–wave interaction has comparable amplitude to those of the stationary wave 1 and the traveling wave 2, and has a node around 60°S, where these primary waves have large amplitude. The transient wave 1 travels eastward with the same angular frequency as that of the traveling wave 2. The polar night jet also vacillates with the same frequency such that it has its minimum when the stationary wave 1 and the transient wave 1 are in phase at the polar side of the node. The vacillation is basically due to quasi-periodic variations of the wave driven by the interference between the stationary and traveling wave 1s. Similar periodic variations of the polar vortex are obtained in the model experiment here, in the circumstance that stationary wave 1 generated by surface topography has comparable amplitude to the eastward-traveling wave 2 that is generated by the barotropic instability of a forced mean zonal wind. The winter polar vortex shows large interannual variability. Similar quasi-periodic variations due to wave– wave interaction often occurred for the 24 yr in late winter when the transient wave 2 was vigorous.

scholarly journals A Parameter Sweep Experiment on Quasiperiodic Variations of a Polar Vortex due to Wave–Wave Interaction in a Spherical Barotropic Model

2007 ◽  
Vol 64 (11) ◽  
pp. 4069-4083 ◽  
Author(s):  
Yasuko Hio ◽  
Shigeo Yoden
Keyword(s):  
Periodic Solution ◽  
Surface Topography ◽  
Traveling Wave ◽  
Dissipative System ◽  
Polar Vortex ◽  
Independent Solution ◽  
Wave Interaction ◽  
Barotropic Model ◽  
Irregular Solution ◽  
Zonal Wavenumber

Abstract Weakly nonlinear aspects of a barotropically unstable polar vortex in a forced–dissipative system with a zonally asymmetric surface topography are investigated in order to obtain a deeper understanding of rather periodic variations of the winter circumpolar vortex in the Southern Hemisphere stratosphere that are characterized by the wave–wave interaction between the stationary planetary wave of zonal wavenumber 1 (denoted as Wave 1) and the eastward traveling Wave 2 as studied by Hio and Yoden in 2004. The authors use a spherical barotropic model with a forcing of zonally symmetric jet, dissipation, and sinusoidal surface topography. A parameter sweep experiment is performed by changing the amplitude of the surface topography, which forces the stationary Wave 1, and the width of the prescribed zonally symmetric jet, which controls the barotropic instability, to generate the traveling Wave 2. Several types of solutions from a time-independent solution to a nonperiodic irregular solution are obtained for the combination of these external parameters, but the predominant solution obtained in a wide parameter space is periodic. Details of the wave–wave interactions are described for the transition from a quasiperiodic vacillation to a periodic solution as the increase of the amplitude of topography. Phase relationships are locked at the transition, and variations of zonal-mean zonal flow and topographically forced Wave 1 synchronize with periodic progression of Wave 2 in the periodic solution. A diagnosis with a low-order “empirical mode expansion” of the vorticity equation gives a limited number of dominant nonlinear triad interactions among the zonal-mean, Wave-1, and Wave-2 components around the transition point.

scholarly journals Anomalous quasi-stationary planetary waves over the Antarctic region in 1988 and 2002

2008 ◽  
Vol 26 (5) ◽  
pp. 1101-1108 ◽  
Author(s):  
A. V. Grytsai ◽  
O. M. Evtushevsky ◽  
G. P. Milinevsky
Keyword(s):  
Lower Stratosphere ◽  
Polar Vortex ◽  
Amplitude Distribution ◽  
Stationary Wave ◽  
Planetary Waves ◽  
Late Winter ◽  
Stratospheric Polar Vortex ◽  
Latitudinal Position ◽  
The Antarctic ◽  
Peak Value

Abstract. Anomalies in the Antarctic total ozone and amplitudes of the quasi-stationary planetary waves in the lower stratosphere temperature during the winter and spring of 1988 and 2002 have been compared. Westward displacement of the quasi-stationary wave (QSW) extremes by 50°–70° relative to the preceding years of the strong stratospheric polar vortex in 1987 and 2001, respectively, was observed. A dependence of the quasi-stationary wave ridge and trough positions on the strength of the westerly zonal wind in the lower stratosphere is shown. Comparison of the QSW amplitude in the lower stratosphere temperature in July and August shows that the amplitude distribution with latitude in August could be considered as a possible indication of the future anomalous warming in Antarctic spring. In August 2002, the QSW amplitude of 10 K at the edge region of the polar vortex (60° S–65° S) preceded the major warming in September, whereas in August 1988, the highest 7 K amplitude at 55° S preceded the large warming in the next months. These results suggest that the peak value of the lower stratosphere temperature QSW amplitude and the peak latitudinal position in late winter can influence the southern polar vortex strength in spring.

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 Evolution of the stratospheric polar vortex edge intensity and duration in the Southern hemisphere over the 1979–2020 period

2021 ◽  
Author(s):  
Audrey Lecouffe ◽  
Sophie Godin-Beekmann ◽  
Andrea Pazmiño ◽  
Alain Hauchecorne
Keyword(s):  
Solar Cycle ◽  
Southern Hemisphere ◽  
Southern Oscillation ◽  
Polar Vortex ◽  
Onset Date ◽  
Late Winter ◽  
Stratospheric Polar Vortex ◽  
The Difference ◽  
Lower Variability

Abstract. The intensity and position of the Southern Hemisphere stratospheric polar vortex edge is evaluated as a function of equivalent latitude over the 1979–2020 period on three isentropic levels (475 K, 550 K and 675 K) from ECMWF ERA-Interim reanalysis. The study also includes an analysis of the onset and breakup dates of the polar vortex, which are determined from wind thresholds (e.g. 15.2 m.s−1, 20 m.s−1and 25 m.s−1) along the vortex edge. The vortex edge is stronger in late winter, over September–October – November with the period of strongest intensity occurring later at the lowermost level. A lower variability of the edge position is observed during the same period. Long-term increase of the vortex edge intensity and break-up date is observed over the 1979–1999 period, linked to the increase of the ozone hole. Long-term decrease of the vortex onset date related to the 25 m.s−1wind threshold is also observed at 475 K during this period. The solar cycle and to a lower extent the quasi-biennal oscillation (QBO) and El Niño Southern Oscillation (ENSO) modulate the inter-annual evolution of the strength of the vortex edge and the vortex breakup dates. Stronger vortex edge and longer vortex duration is observed in solar minimum (minSC) years, with the QBO and ENSO further modulating the solar cycle influence, especially at 475 K and 550 K: during West QBO (wQBO) phases, the difference between vortex edge intensity for minSC and maxSC years is smaller than during East QBO (eQBO) phases. The polar vortex edge is stronger and lasts longer for maxSC/wQBO years than for maxSC/eQBO years. ENSO has a weaker impact but the vortex edge is somewhat stronger during cold ENSO phases for both minSC and maxSC years.

Airborne in situ tracer observations in the 2019 Springtime Antarctic UTLS during the HALO SouthTRAC campaign

2020 ◽  
Author(s):  
C. Michael Volk ◽  
Valentin Lauther ◽  
Andrea Rau ◽  
Fridolin Hader ◽  
Svetlana Cvetkova
Keyword(s):  
High Altitude ◽  
Southern Hemisphere ◽  
Polar Vortex ◽  
Rio Grande ◽  
Late Winter ◽  
Tracer Transport ◽  
Rossby Wave Breaking ◽  
The Antarctic ◽  
The Impact

<p>During the recent SouthTRAC (Transport and composition of the Southern Hemisphere UTLS) campaign the German High Altitude and LOng range research aircraft (HALO) intensively probed the bottom of the Antarctic vortex and the adjacent mid to high latitude upper troposphere / lower stratosphere (UTLS) throughout late winter and spring 2019.  A main goal of this mission was to study dynamics, transport and composition of this region, and particularly to assess the impact of the Antarctic vortex on the southern hemisphere UTLS.  The Antarctic winter 2019 was extraordinary with respect to dynamics, with a sudden stratospheric warming (only the second one ever observed) leading to a less stable and unusually warm polar vortex. The campaign consisted of two phases based in Rio Grande, Argentina (54°S) and comprised a total of 27 science flights including transfer flights to/from Argentina and 13 local flights from Rio Grande in September/early October and in November 2019.  A number of these flights penetrated into the lower Antarctic vortex, others crossed streamers or thin filaments shed from the vortex by frequent Rossby wave breaking events.</p><p>We present observations obtained on board of HALO by the University of Wuppertal's High Altitude Gas Analyzer –V (HAGAR-V), a 5-channel in-situ tracer instrument recently developed for HALO to study the chemical composition, dynamics, and transport in the UTLS.  HAGAR-V combines i) a fast CO<sub>2</sub> measurement by NDIR analyzer (every 3 s), ii) a 2-channel GC/ECD-system measuring the long-lived tracers CFC-12, SF<sub>6</sub> (every 40 s), CFC-11, CFC-113 and Halon-1211 (every 80s), and iii) a 2-channel GC/MS system measuring a large suite of further long-lived (e.g. HFCs) and short-lived halogenated tracers, including further chlorine source gases (e.g. CCl<sub>4</sub>, CH<sub>2</sub>Cl<sub>2</sub>, CHCl<sub>3</sub>, C<sub>2</sub>Cl<sub>4</sub>, HCFCs) every 2-4 minutes.  We will discuss the unusually active dynamics and associated tracer transport in the vicinity of the 2019 Antarctic vortex reflected by these measurements, and show the temporal development of vertical distributions and tracer correlations throughout the spring.  We will also compare the tracer distributions during SouthTRAC with those observed from the M55 Geophysica aircraft during the 1999 Antarctic campaign APE-GAIA.</p>

scholarly journals A Very Large, Spontaneous Stratospheric Sudden Warming in a Simple AGCM: A Prototype for the Southern Hemisphere Warming of 2002?

2005 ◽  
Vol 62 (3) ◽  
pp. 890-897 ◽  
Author(s):  
Paul J. Kushner ◽  
Lorenzo M. Polvani
Keyword(s):  
Southern Hemisphere ◽  
Polar Vortex ◽  
Wave Interaction ◽  
Equation Model ◽  
Wave Activity ◽  
Stationary Waves ◽  
Baroclinic Wave ◽  
Primitive Equation ◽  
Stratospheric Sudden Warming ◽  
Insight Into

Abstract An exceptionally strong stratospheric sudden warming (SSW) that spontaneously occurs in a very simple stratosphere–troposphere AGCM is discussed. The model is a dry, hydrostatic, primitive equation model without planetary stationary waves. Transient baroclinic wave–wave interaction in the troposphere thus provides the only source of upward-propagating wave activity into the stratosphere. The model’s SSW is grossly similar to the Southern Hemisphere major SSW of 2002: it occurs after weaker warmings “precondition” the polar vortex for breaking, it involves a split of the polar vortex, and it has a downward-propagating signature. These similarities suggest that the Southern Hemisphere SSW of 2002 might itself have been caused by transient baroclinic wave–wave interaction. The simple model used for this study also provides some insight into how often such extreme events might occur. The frequency distribution of SSWs in the model has exponential, as opposed to Gaussian, tails. This suggests that very large amplitude SSWs, though rare, might occur with higher frequency than might be naively expected.

scholarly journals Chemical ozone loss and ozone mini-hole event during the Arctic winter 2010/2011 as observed by SCIAMACHY and GOME-2

2014 ◽  
Vol 14 (7) ◽  
pp. 3247-3276 ◽  
Author(s):  
R. Hommel ◽  
K.-U. Eichmann ◽  
J. Aschmann ◽  
K. Bramstedt ◽  
M. Weber ◽  
...  
Keyword(s):  
Transport Model ◽  
Polar Vortex ◽  
The Arctic ◽  
Optical Absorption Spectroscopy ◽  
Late Winter ◽  
Total Column Ozone ◽  
Bromine Oxide ◽  
Ozone Loss ◽  
Catalytic Cycles ◽  
Total Column

Abstract. Record breaking loss of ozone (O3) in the Arctic stratosphere has been reported in winter–spring 2010/2011. We examine in detail the composition and transformations occurring in the Arctic polar vortex using total column and vertical profile data products for O3, bromine oxide (BrO), nitrogen dioxide (NO2), chlorine dioxide (OClO), and polar stratospheric clouds (PSC) retrieved from measurements made by SCIAMACHY (Scanning Imaging Absorption SpectroMeter for Atmospheric CHartography) on-board Envisat (Environmental Satellite), as well as total column ozone amount, retrieved from the measurements of GOME-2 (Global Ozone Monitoring Experiment) on MetOp-A (Meteorological Experimental Satellite). Similarly we use the retrieved data from DOAS (Differential Optical Absorption Spectroscopy) measurements made in Ny-Ålesund (78.55° N, 11.55° E). A chemical transport model (CTM) has been used to relate and compare Arctic winter–spring conditions in 2011 with those in the previous year. In late winter–spring 2010/2011 the chemical ozone loss in the polar vortex derived from SCIAMACHY observations confirms findings reported elsewhere. More than 70% of O3 was depleted by halogen catalytic cycles between the 425 and 525 K isentropic surfaces, i.e. in the altitude range ~16–20 km. In contrast, during the same period in the previous winter 2009/2010, a typical warm Arctic winter, only slightly more than 20% depletion occurred below 20 km, while 40% of O3 was removed above the 575 K isentrope (~23 km). This loss above 575 K is explained by the catalytic destruction by NOx descending from the mesosphere. In both Arctic winters 2009/2010 and 2010/2011, calculated O3 losses from the CTM are in good agreement to our observations and other model studies. The mid-winter 2011 conditions, prior to the catalytic cycles being fully effective, are also investigated. Surprisingly, a significant loss of O3 around 60%, previously not discussed in detail, is observed in mid-January 2011 below 500 K (~19 km) and sustained for approximately 1 week. The low O3 region had an exceptionally large spatial extent. The situation was caused by two independently evolving tropopause elevations over the Asian continent. Induced adiabatic cooling of the stratosphere favoured the formation of PSC, increased the amount of active chlorine for a short time, and potentially contributed to higher polar ozone loss later in spring.

scholarly journals Fundamental solutions for the long–short-wave interaction system

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 1093-1099
Author(s):  
Mustafa Inc ◽  
Samia Zaki Hassan ◽  
Mahmoud Abdelrahman ◽  
Reem Abdalaziz Alomair ◽  
Yu-Ming Chu
Keyword(s):  
Fluid Mechanics ◽  
Traveling Wave ◽  
Inverse Method ◽  
Nonlinear Partial Differential Equations ◽  
Traveling Wave Solutions ◽  
Wave Interaction ◽  
Fundamental Solutions ◽  
Short Wave ◽  
Wave Solutions ◽  
Physical Environments

Abstract In this article, the system for the long–short-wave interaction (LS) system is considered. In order to construct some new traveling wave solutions, He’s semi-inverse method is implemented. These solutions may be applicable for some physical environments, such as physics and fluid mechanics. These new solutions show that the proposed method is easy to apply and the proposed technique is a very powerful tool to solve many other nonlinear partial differential equations in applied science.

Turbulent kinetic energy spectra and cascades in the polar atmosphere of Saturn

2021 ◽  
Author(s):  
Peter L. Read ◽  
Arrate Antuñano ◽  
Simon Cabanes ◽  
Greg Colyer ◽  
Teresa del Rio-Gaztelurrutia ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
High Latitude ◽  
Deep Convection ◽  
Baroclinic Instability ◽  
Polar Vortex ◽  
Energy Spectra ◽  
Horizontal Wind ◽  
Polar Regions ◽  
Zonal Wavenumber ◽  
Cloud Tops

<p>The regions of Saturn’s cloud-covered atmosphere polewards of 60<sup>o</sup> latitude are dominated in each hemisphere near the cloud tops by an intense, cyclonic polar vortex surrounded by a strong, high latitude eastward zonal jet. In the north, this high latitude jet takes the form of a remarkably regular zonal wavenumber m=6 hexagonal pattern that has been present at least since the Voyager spacecraft encounters with Saturn in 1980-81, and probably much longer. The origin of this feature, and the absence of a similar feature in the south, has remained poorly understood since its discovery. In this work, we present some new analyses of horizontal wind measurements at Saturn’s cloud tops polewards of 60 degrees in both the northern and southern hemispheres, previously published by Antuñano et al. (2015) using images from the Cassini mission, in which we compute kinetic energy spectra and the transfer rates of kinetic energy (KE) and enstrophy between different scales. 2D KE spectra are consistent with a zonostrophic regime, with a steep (~n<sup>-5</sup>) spectrum for the mean zonal flow (n is the total wavenumber) and a shallower Kolmogorov-like KE spectrum (~n<sup>-5/3</sup>) for the residual (eddy) flow, much as previously found for Jupiter’s atmosphere (Galperin et al. 2014; Young & Read 2017). Three different methods are used to compute the energy and enstrophy transfers, (a) as latitude-dependent zonal spectral fluxes, (b) as latitude-dependent structure functions and (c) as spatially filtered energy fluxes. The results of all three methods are largely in agreement in indicating a direct (forward) enstrophy cascade across most scales, averaged across the whole domain, an inverse kinetic energy cascade to large scales and a weak direct KE cascade at the smallest scales. The pattern of transfers has a more complex dependence on latitude, however. But it is clear that the m=6 North Polar Hexagon (NPH) wave was transferring KE into its zonal jet at 78<sup>o</sup> N (planetographic) at a rate of ∏<sub>E</sub> ≈ 1.8 x 10<sup>-4</sup> W kg<sup>-1</sup> at the time the Cassini images were acquired. This implies that the NPH was not maintained by a barotropic instability at this time, but may have been driven via a baroclinic instability or possibly from deep convection. Further implications of these results will be discussed.</p><p> </p><p>References</p><p>Antuñano, A., T. del Río-Gaztelurrutia, A. Sánchez-Lavega, and R. Hueso (2015), Dynamics of Saturn’s polar regions, J. Geophys. Res. Planets, 120, 155–176, doi:10.1002/2014JE004709.</p><p>Galperin, B., R. M.B. Young, S. Sukoriansky, N. Dikovskaya, P. L. Read, A. J. Lancaster & D. Armstrong (2014) Cassini observations reveal a regime of zonostrophic macroturbulence on Jupiter, Icarus, 229, 295–320.doi: 10.1016/j.icarus.2013.08.030</p><p>Young, R. M. B. & Read, P. L. (2017) Forward and inverse kinetic energy cascades in Jupiter’s turbulent weather layer, Nature Phys., 13, 1135-1140. Doi:10.1038/NPHYS4227</p><div> <div> <div> </div> </div> <div> <div> </div> </div> <div> <div> </div> </div> <div> <div> </div> </div> </div>

scholarly journals Nonstationarity in Southern Hemisphere Climate Variability Associated with the Seasonal Breakdown of the Stratospheric Polar Vortex

2017 ◽  
Vol 30 (18) ◽  
pp. 7125-7139 ◽  
Author(s):  
Nicholas J. Byrne ◽  
Theodore G. Shepherd ◽  
Tim Woollings ◽  
R. Alan Plumb
Keyword(s):  
Climate Variability ◽  
Southern Hemisphere ◽  
Seasonal Cycle ◽  
Vortex Breakdown ◽  
Polar Vortex ◽  
Reanalysis Data ◽  
Early Summer ◽  
Stratospheric Polar Vortex ◽  
Time Symmetry

Abstract Statistical models of climate generally regard climate variability as anomalies about a climatological seasonal cycle, which are treated as a stationary stochastic process plus a long-term seasonally dependent trend. However, the climate system has deterministic aspects apart from the climatological seasonal cycle and long-term trends, and the assumption of stationary statistics is only an approximation. The variability of the Southern Hemisphere zonal-mean circulation in the period encompassing late spring and summer is an important climate phenomenon and has been the subject of numerous studies. It is shown here, using reanalysis data, that this variability is rendered highly nonstationary by the organizing influence of the seasonal breakdown of the stratospheric polar vortex, which breaks time symmetry. It is argued that the zonal-mean tropospheric circulation variability during this period is best viewed as interannual variability in the transition between the springtime and summertime regimes induced by variability in the vortex breakdown. In particular, the apparent long-term poleward jet shift during the early-summer season can be more simply understood as a delay in the equatorward shift associated with this regime transition. The implications of such a perspective for various open questions are discussed.

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