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Etienne Dunn-Sigouin and Tiffany Shaw

1. Introduction Vertical coupling by planetary-scale waves dominates the variability of the wintertime stratospheric circulation ( Plumb 2010 ). Upward planetary wave coupling from the troposphere to the stratosphere is often diagnosed using the zonal-mean meridional eddy heat flux υ ′ T ′ ¯ , where primes denote deviations from the zonal mean (eddies) and the bar denotes the zonal mean, since positive values are consistent with an upward wave group velocity according to linear theory

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Charles McLandress, Theodore G. Shepherd, Saroja Polavarapu, and Stephen R. Beagley

, particularly if accurate predictions of future Antarctic lower-stratospheric ozone and SH climate change are to be obtained. The fact that nearly all CCMs suffer from a cold-pole bias in SH winter and spring points to missing stratospheric wave drag. This could be small-scale gravity wave drag (GWD), resolved (planetary) wave drag, or a combination of the two. Since both forms of wave drag respond to the mean winds, there is a strong coupling between them ( McLandress and McFarlane 1993 ) and it is not

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Nicholas J. Lutsko and Isaac M. Held

. Rev. , 99 , 564 – 576 , doi: 10.1175/1520-0493(1971)099<0564:TROAMM>2.3.CO;2 . Egger , J. , 1978 : Dynamics of blocking highs . J. Atmos. Sci. , 35 , 1788 – 1801 , doi: 10.1175/1520-0469(1978)035<1788:DOBH>2.0.CO;2 . Esler , J. G. , L. M. Polvani , and R. A. Plumb , 2000 : The effect of a Hadley circulation on the propagation and reflection of planetary waves in a simple one-layer model . J. Atmos. Sci. , 57 , 1536 – 1556 , doi: 10.1175/1520-0469(2000)057<1536:TEOAHC>2.0.CO;2

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Etienne Dunn-Sigouin and Tiffany Shaw

Polvani 2009 ; Hitchcock and Simpson 2014 ; Hitchcock and Haynes 2016 ; Smith and Scott 2016 ). Consistently, the accurate representation of extreme vortex events in forecast models enhances subseasonal to seasonal prediction skill of the wintertime extratropical troposphere (e.g., Sigmond et al. 2013 ; Tripathi et al. 2015 ; Scaife et al. 2016 ; Hansen et al. 2017 ). An important driver of zonal-mean stratospheric variability is vertical coupling by planetary waves generated in the troposphere

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Nicholas J. Lutsko

other impacts of small-scale orography is notoriously difficult, yet is essential for making accurate weather forecasts and for predicting future circulation changes [see Sandu et al. (2019) for a recent review]. At larger scales, orographically forced quasi-stationary planetary waves transport substantial amounts of heat, moisture and momentum through the atmosphere, exerting a strong control on regional climates and also playing a key role in the zonal-mean circulation. Our understanding of

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C. Schnadt Poberaj, J. Staehelin, and D. Brunner

radiative heating and/or an enhanced upward flux of planetary wave activity from the troposphere. The QBO is a downward-propagating variation of easterly and westerly winds with a variable period of about 28 months caused by vertically propagating equatorial waves (e.g., Baldwin et al. 2001 ). The QBO forcing induces a direct meridional circulation at low to midlatitudes (e.g., Kinnersley and Tung 1999 ) and is responsible for the so-called ozone QBO: in the tropics, positive (negative) column ozone

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Yoshikazu Hayashi

JUNE 1981 YOSHIKAZU HAYASHI 1197Vertical-Zonal Propagation of a Stationary Planetary Wave Packet YOSHIKAZU HAYASHIGeophysical Fluid Dynamics Laboratory/NOAA, Princeton University, Princeton, NJ 08540(Manuscript received 7 August 1980, in final form 9 February 1981)ABSTRACT In order to explain why the Aleutian high stands out in the winter stratosphere, a complex Fourieranalysis

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Charles A. Lin

VOL. 37, NO. 11JOURNAL OF THE ATMOSPHERIC SCIENCESNOVEMBER 1980 ,Eddy Heat Fluxes and Stability of Planetary Waves. Part I CHARLES A. LIN'Canadian Climate Centre, Downsview, Ontario, Canada M3H 5T4(Manuscript received 29 October 1979, in final form 14 August 1980)ABSTRACTThe stability of baroclinic Rossby waves in a zonal shear flow is examined. The model used is alinear, quasi-geostrophic, two-level, adiabatic and frictionless midlatitude P-plane model. The perturbations consist

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Paolo Ruggieri, Maarten H. P. Ambaum, and Jonas Nycander

Plumb (2002) . Synoptic waves induce a symmetric circulation (with respect to the equator) in the lower stratosphere with air rising in the tropics and falling in the extratropics. Planetary, quasi-stationary waves perturb the core of the stratosphere, inducing an interhemispheric cell, with upward motion at low latitudes and sinking motion in winter polar latitudes. Gravity waves drive a global cell in the mesosphere. The stratosphere can be thought of as divided into four regions with specific

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Dehai Luo, Linhao Zhong, and Christian L. E. Franzke

the results is given in the final section. 2. Wave–eddy interaction model and its nonlinear multiscale interaction solutions a. The nonlinear multiscale interaction model in a quasigeostrophic barotropic atmosphere In this paper, the NAO anomaly is a planetary-scale wave; thus, the NAO–eddy interaction may be referred to as the wave–eddy interaction herein. To reveal their instantaneous relationship, it is necessary to present the analytical solution of the wave–eddy interaction model derived in

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