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Timothy J. Dunkerton and Richard K. Scott

1. Introduction The concept of “geophysical turbulence” when applied to the large-scale circulation of planetary atmospheres must account for the emergence of coherent structures, most notably zonal jets of alternating sign that organize the turbulence into latitudinal bands. This result is consistent with the role of Rossby waves in arresting the upscale cascade of energy in barotropic or geostrophic turbulence ( Rhines 1975 ; Williams 1978 ). Certain fundamental characteristics of turbulence

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R. K. Smith

NOVEMBER 1969 R. K. SMITH 1233On the Effects of Vorticity Entrainment in Zonal Jet FlowsR. K. SmTI~Dept. of Mathematics, Monash University, Clayton, Victoria, Australia (Manuscript received 30 December 1968)ABSTRACT There is a tendency for certain flows in the atmosphere and oceans to concentrate into narro~v streamsor currents, which preserve their identity over very large distances

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Chester W. Newton

638JOURNAL OF METEOROLOGYVOLUME 16AXIAL VELOCITY STREAKS IN THE JET STREAM: AGEOSTROPHIC "INERTIAL'' OSCILLATIONSBy Chester W. Newton The University of Chicago1(Manuscript received 17 February 1959)ABSTRACTAn air particle alternately speeds up and slows down as it passes through local isotach maxima. It isshown that, on the average, the observed period of such speed variations in the core of the jet stream isabout twice the period of an inertial oscillation. Periods are somewhat longer for

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Frank B. Lipps

MARcel966 FRANK B. LIPPS 213Momentum Transfer Across an Asymmetric Jet~ FRANK B. LIPPS2The University of Chicago and the Environmental Science Services Administration(Manuscript received 6 November 1964, in revised form 21 October 1965)ABSTRACT The northward momentum transfer across an asymmetric jet in a three-dimensional atmosphere is ex~amined by means of

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Francis Codron

Solomon 2002 ), the observed Southern Hemisphere response to El Niño ( Seager et al. 2003 ; L’Heureux and Thompson 2006 ), as well as the modeled response to greenhouse gas increase ( Kushner et al. 2001 ) or ozone depletion ( Gillett and Thompson 2003 ; Arblaster and Meehl 2006 ). From the physical point of view, annular modes have been studied in association with the dynamics of zonally averaged wind fluctuations. The variability of a zonal eddy-driven jet is dominated by a dipolar, equivalent

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Peter Hitchcock, Peter H. Haynes, William J. Randel, and Thomas Birner

1. Introduction The quasi-biennial oscillation (QBO) is the dominant pattern of variability in the tropical lower stratosphere, characterized by alternating descent of easterly and westerly zonal jets with a period of roughly 28 months. In early 2016, a shallow broad easterly jet emerged in the tropical lower stratosphere, disrupting the QBO by splitting a descending westerly jet roughly in half. This occurrence was unprecedented in more than 50 years of observations ( Newman et al. 2016

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Qin Xu, Ming Liu, and Douglas L. Westphal

1. Introduction The recent numerical study of Liu et al. (2000, hereafter referred to as L00) identified a previously undocumented northerly low-level jet event occurring along the Lut Desert valley into the Jaz Mūrīān dry lake in southern Iran under the influence of a synoptic-scale pressure gradient force and lower-level upstream cold air supply on 12–14 February 1995. The Lut Desert is an elongated confluent valley oriented north–northwest to south–southeast along the foothills of the

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H. L. Kuo

2360 JOURNAL OF THE ATMOSPHERIC SCIENCES VOLUME36Baroelinic Instabilities of Linear and Jet Profiles in the Atmosphere El. L. KvoDepartment of the Geophysical Sciences. The University of Chicag0, Chicago. IL 60637(Manuscript received 11 October 1978, in final form 6 July 1979) ABSTRACT The baroclinic instabilities of double- and single-jet profiles

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A. J. Manfroi and W. R. Young

1. Introduction The inverse cascade, or negative viscosity, is a characteristic feature of two-dimensional turbulence. Our interest here is the arrest of this cascade on a β plane by the spontaneous formation of zonal jets. The early turbulence simulations of Rhines (1975) and Williams (1978) showed that the β effect prevents large meridional (i.e., “cross- β ”) fluid excursions. Instead, zonally elongated, persistent flows extend unimpeded across the computational domain. An important

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S. K. Mishra, D. Subrahmanyam, and M. K. Tandon

2164 JOURNAL OF THE ATMOSPHERIC SCIENCESDivergent Barotropic Instability of the Tropical Asymmetric Easterly JetS. K. MISHRA, D. SUBRAHMANYAM AND M. K. TANDONIndian Institute of Tropical Meteorology, Pune-411 005(Manuscript received 29 October 1980, in final form 11 M. ay 1981)ABSTRACT The divergent barotropic instability of a zonally averaged, observed, tropical, upper tropospheric,monsoon easterly jet is investigated by numerical integration of a linear

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