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Juan Fang and Fuqing Zhang

1. Introduction Tropical cyclone (TC) formation is a complex problem in dynamical and tropical meteorology because it involves interactions among physical processes that vary over multiple space and time scales. The large-scale climatological conditions favorable for the formation of TCs have been well known since Gray (1968) and were summarized later by Briegel and Frank (1997) and others: sea surface temperature of at least 26.5°C coupled with a relatively deep thermocline, organized deep

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Joseph Pedlosky

a wide class offlows in the two-layer model must be stable for sufficiently high zonal wave number.1. Introduction One of the most striking features of the at~nosphericgeneral circulation is the presence of large-scale traveling waves in the westerlies in middle latitudes. It is nowgenerally recognized that these "cyclone" waves playan essential role in the maintenance of the generalcirculation against frictional dissipation. (See, forexample, Starr, 1954.) Large-scale wave motions

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James S. Risbey, Terence J. O’Kane, Didier P. Monselesan, Christian Franzke, and Illia Horenko

1. Introduction The background flow fields in the atmosphere are inherently unstable and support a wide range of modal structures, including large-scale, low-frequency modes ( Frederiksen and Webster 1988 ). The Northern Hemisphere extratropical circulation is characterized by a number of temporally and spatially coherent large-scale structures or teleconnection patterns ( Wallace and Gutzler 1981 ). The regional manifestations of these patterns include the North Atlantic Oscillation (NAO

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Ulrich Achatz, Ulrike Löbl, Stamen I. Dolaptchiev, and Andrey Gritsun

the atmosphere: A numerical experiment . Quart. J. Roy. Meteor. Soc. , 82 , 123 – 164 . Phillips , N. , 1963 : Geostrophic motion . Rev. Geophys. , 1 , 123 –176 , doi:10.1029/RG001i002p00123 . Risken , H. , 1984 : The Fokker-Plank Equation: Methods of Solution and Applications. Springer-Verlag, 474 pp. Robinson , A. , and H. Stommel , 1959 : The oceanic thermocline and the associated thermohaline circulation . Tellus , 11 , 295 – 308 . Selten , F. M. , 1995 : An efficient

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Ding Ma, Pedram Hassanzadeh, and Zhiming Kuang

1. Introduction The annular mode is a dominant pattern of extratropical circulation variability in both hemispheres on intraseasonal to interannual time scales ( Kidson 1988 ; Thompson and Wallace 1998 ; Gong and Wang 1999 ; Thompson and Wallace 2000 ). The annular mode corresponds to the leading empirical orthogonal function (EOF) of zonal-mean zonal wind, which features an equivalent barotropic dipolar structure and represents latitudinal shifts of the eddy-driven midlatitude jet ( Nigam

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Bin Wang

episodes ( 1982-83 and 1986-87) exhibit some common features intheir development and vertical structure. These features are examined by multivariate empirical orthogonalfunction analysis of the interannual variability of the ocean-atmosphere system along ~quatorial Indian andPacific oceans. The updraft and downdrat~ branches of the anomalous Walker circulation originate over the western Pacificand the ~ru Indian Ocean, rcsp~vcly. The early development of basinwidc warming is characterized bythe

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Duane E. Waliser, K. M. Lau, and Jae-Hoon Kim

-related anomalies in convection and the large-scale circulation are strongest in the Eastern Hemisphere, over the Indian and western Pacific Oceans, where the oscillation exhibits its greatest variability and typically reaches its maximum amplitude. Such interactions strongly influence the onset and activity of the Asian–Australian monsoon system (e.g., Yasunari 1979 , 1980 ; Hendon and Liebmann 1990a , 1990b ) and have also been shown to influence extratropical regions as well (e.g., Weickmann 1983

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T. N. Krishnamurti and D. R. Chakraborty

oscillations (CISO). Their study reveals that the CISO results from a phase locking of transient intraseasonal oscillations with the annual cycle. Using a modified Cane and Zebiak (1985) model that includes the seasonal variations of the western Pacific wind anomalies and the basic-state thermocline depth, the peaks of La Niña seem to prefer the boreal winter, suggesting that the seasonal variation of the western Pacific surface wind anomalies and the mean thermocline depth are critical factors for the

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Haixiong Zhuang, Xiaojun Yang, and Zhenling Wu

–ocean surface interaction. In this study, a new atmosphere–ocean surface interaction scheme (AOSIS) for the simulation of these exchanges and SST is presented. In AOSIS, the ocean surface energy balance equation is solved, and the temperatures of the sea surface, ocean mixed layer, and thermocline are estimated. For the treatment of the aerodynamic transfers in the atmosphere, a new algorithm for computing the ocean surface aerodynamic roughness length is introduced. The framework of AOSIS is depicted in

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Miguel A. C. Teixeira, Alexandre Paci, and Anne Belleudy

), decelerating the mean circulation, an effect that is typically unresolved by those models ( Stensrud 2009 ; Teixeira 2014 ). The importance of trapped waves propagating at temperature inversions has only been recognized more recently, in particular in connection with the occurrence of lee-wave rotors ( Vosper 2004 ; Hertenstein 2009 ; Knigge et al. 2010 ), although early allusions to this kind of waves go back to the pioneering work of Scorer (1949 , 1953 , 1954) . In the ocean, trapped waves are

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