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R. K. Scott and P. H. Haynes

of a wave-driven mean flow with relaxation to a basic state. The quasi-geostrophic shallow-water equations in a β channel, with only one meridional and one zonal Fourier mode, reduce under quasi-static assumptions to where u is the zonal mean zonal velocity, u r is some radiative basic-state velocity, α is the relaxation rate, and D ( u ; h b ) is the steady-state wave drag associated with a particular u and planetary wave boundary forcing h b ( Charney and DeVore 1979 ; Held 1983

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G. A. Jones and S. K. Avery

circulation and planetary-wave winds on the'distribution of nitric oxide inthe 55-120 kra height region is investigated. A time-dependent numerical model is used to investigate theinteraction between l~lanetary waves and the zonal mean circulation, and the effect of the circulation on thenitric oxide distribution is determined. The initial nitric oxide NO) distribution is obtained by using a simplesource/sink chemistry, vertical eddy diffusion, and advective transport by the zonal mean circulation

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D. Jacqmin and R. S. Lindzen

724 JOURNAL OF THE 'ATMOSPHERIC SCIENCES VOL. 42, NO. 7The Causation and Sensitivity of the Northern W~nter Planetary Waves D. JACQMINICenter for Earth and Planetary Physics, Harvard University, Cambridge, MA 02138 R. S. LINDZENCenter for Meteorology and Physical Oceanography, Massachusetts Institute of Technology, Cambridge, MA 02139(Manuscript received 4 June 1984, in

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D. G. Andrews and M. F. McIntyre

NOVEMBER 1976 D. G. A N D R E W S A N D M. E. M c I N T Y R E 2049Planetary Waves in Horizontal and Vertical Shear: Asymptotic Theory for Equatorial Waves in Weak Shear D. G. A~)~ws AND M. E. MclN~r~U. K. Universities' Atmospheri~ Modelling Group, Department of Geophysics, University of Reading and Department of Applied Mall~ematics and Theoretical Physics, University of Cambridge

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M. M. Hurwitz, P. A. Newman, L. D. Oman, and A. M. Molod

et al. 2006 ; Cagnazzo et al. 2009 ). Warming of the Arctic stratosphere is a response to increased planetary wave driving: Garfinkel and Hartmann (2008) showed that the extratropical tropospheric teleconnections produced during El Niño events weaken the Arctic vortex, leading to higher stratospheric temperatures during the NH winter season. The phase of the quasi-biennial oscillation (QBO) ( Garfinkel and Hartmann 2007 ; Bronnimann 2007 ) and volcanic activity ( Randel et al. 2009 ) modulate

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Masaru Yamamoto

traveling equatorial waves are important in the redistribution of angular momentum. Covey and Schubert (1981a , 1982) and Smith et al. (1992 , 1993) examined linear responses of planetary-scale waves in the Venus atmosphere, and pointed out that the global-scale UV oscillations with the 4-day period are associated with the resonant waves. In the case that resonant wave has the critical level near the low-stability layer (∼55 km) where buoyancy frequency ( N ) is very low, the nonlinear effects of

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William H. Hooke and R. Michael Jones

2048JOURNAL OF THE ATMOSPHERIC SCIENCESVOL. 43, No. 19Dissipative Waves Excited by Gravity-Wave Encounterswith the Stably Stratified Planetary Boundary Layer WILLIAM H. HWKE AND R. MICHAEL JONESEnvironmental Research Laboratories, National Oceanic and Atmospheric Administration. Boulder, CO 80303 (Manuscript received 19 September 1985, in final form 2 April 1986) ABSTRACTWe suggest that the strata of strong echo returns frequently revealed by remote

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Tim Li and Chunhua Zhou

1. Introduction An outstanding question about the Madden–Julian Oscillation (MJO; Madden and Julian 1971 , 1972 ) is why the oscillation prefers a planetary zonal scale. There have been a number of theoretical studies aimed at addressing this scale selection issue. Chang (1977) proposed that the MJO can be represented by convectively driven equatorial Kelvin waves. However, the wave–conditional instability of second kind (CISK) mechanism prefers the most unstable growth at a shorter zonal

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Navid C. Constantinou, Brian F. Farrell, and Petros J. Ioannou

1. Introduction A regime in which jets, planetary-scale waves, and vortices coexist is commonly observed in the turbulence of planetary atmospheres, with the banded winds and embedded vortices of Jupiter and the Saturn North Polar vortex constituting familiar examples ( Vasavada and Showman 2005 ; Sánchez-Lavega et al. 2014 ). Planetary-scale waves in the jet stream and vortices, such as cutoff lows, are also commonly observed in Earth’s atmosphere. Conservation of energy and enstrophy in

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H-L. Liu, F. Sassi, and R. R. Garcia

1989 ; Smith et al. 2003 ), and the Met Office (UKMO) Stratosphere–Mesosphere Model (SMM) ( Gray et al. 2003 ). The lower boundaries of these models are specified, either by reanalysis data or by idealized formulation, to account for planetary waves and tides. TIME-GCM extends from the stratosphere (∼30 km) to the upper thermosphere, and the vertical ranges of ROSE and SMM are 15–110 km and 16–80 km, respectively. Examples of the latter include the Middle Atmosphere Circulation Model at Kyushu

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