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Paul E. Roundy

, 1994 : The life cycle of the Madden–Julian oscillation . J. Atmos. Sci. , 51 , 2225 – 2237 . Hendon , H. H. , and M. C. Wheeler , 2008 : Some space–time spectral analyses of tropical convection and planetary-scale waves . J. Atmos. Sci. , 65 , 2936 – 2948 . Kalnay , E. , and Coauthors , 1996 : The NCEP/NCAR 40-Year Reanalysis Project . Bull. Amer. Meteor. Soc. , 77 , 437 – 471 . Kikuchi , K. , and B. Wang , 2010 : Spatiotemporal wavelet transform and the multiscale

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Min Wen
,
Song Yang
,
Augustin Vintzileos
,
Wayne Higgins
, and
Renhe Zhang

experiment with the particular system. Yang et al. (2008b) have briefly shown the improvement in simulating the Asian summer monsoon from resolution T62 to resolution T126 over the Tibetan Plateau and the tropical Indian Ocean, but the discussion was based on the results from two free runs. Achuthavarier and Krishnamurthy (2010) claimed that the improvement in monsoon simulation with model resolution was only marginal. Many of the studies reviewed above have also analyzed the features of monsoons

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Anantha Aiyyer
,
Ademe Mekonnen
, and
Carl J. Schreck III

1. Introduction Convection-coupled waves are an integral part of atmospheric variability in the tropics (e.g., Gruber 1974 ; Takayabu 1994 ; Wheeler and Kiladis 1999 ). Numerous studies have found that they modulate precipitation, atmospheric momentum transport. and tropical cyclone (TC) activity (e.g., Liebmann et al. 1994 ; Lin et al. 2005 ; Bessafi and Wheeler 2006 ). Accurate assessment of climatological wave activity is essential for a complete description of tropical circulation and

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Joowan Kim
and
Seok-Woo Son

that enters the stratosphere through the tropical tropopause undergoes a freeze-drying process near the CPT ( Brewer 1949 ), the amount of water vapor transported into the stratosphere is highly dependent on thermal characteristics of the CPT ( Holton et al. 1995 ; Mote et al. 1996 ). It is known that small changes in water vapor in the stratosphere can drive significant changes in the climate below by modifying the global radiation budget ( Holton et al. 1995 ; de F. Forster and Shine 1999

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Kyong-Hwan Seo
,
Jin-Ho Choi
, and
Sang-Dae Han

trapped, zonally propagating tropical circulations. Later, Takayabu (1994) and Wheeler and Kiladis (1999) explicitly demonstrated the existence of coupled anomalies of deep convection and large-scale circulation in the tropics. Now these waves are well known to compose a nonnegligible fraction of submonthly tropical variability ( Kiladis et al. 2009 ; Straub et al. 2010 ). Recent studies revealed remarkable self-similar vertical dynamical–thermodynamical wave structures among CCEWs and the Madden

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Bo Wu
,
Tianjun Zhou
, and
Tim Li

1. Introduction During ENSO mature winter, the sea surface temperature anomalies (SSTAs) in the tropical Indian Ocean (TIO) evolve to a basin-scale uniform mode, referred to as Indian Ocean basin mode (IOBM) ( Klein et al. 1999 ; Huang and Kinter 2002 ; Krishnamurthy and Kirtman 2003 ). The IOBM is generally seen as a response to ENSO remote forcing ( Klein et al. 1999 ; Venzke et al. 2000 ; Alexander et al. 2002 ; Lau and Nath 2003 ). The warm SSTA in the equatorial central

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Ken-Chung Ko
,
Huang-Hsiung Hsu
, and
Chia Chou

1. Introduction The multiscale nature of circulation in the tropical western North Pacific (WNP) has become an interesting subject in recent years (e.g., Holland 1995 ; Hsu 2005 ). These multiscale features include monsoon circulation, intraseasonal oscillation (ISO), 3–8-day synoptic waves, and tropical cyclones (TCs). It has been reported in numerous studies that TCs tend to form and develop in the favorable condition provided by the large-scale tropical circulation (e.g., Carr and

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Michael J. Ventrice
,
Christopher D. Thorncroft
, and
Carl J. Schreck III

1. Introduction Tropical cyclones commonly form when sea surface temperatures are warm and when large-scale environmental conditions (e.g., low-moderate vertical wind shear, increased low-to-midlevel moisture, and sufficient low-level cyclonic relative vorticity) are favorable for tropical cyclogenesis ( Gray 1968 , 1988 , 1998 ). Such conditions are known to vary on different time scales. At multidecadal time scales, the environment over the Atlantic has been shown to vary with the Atlantic

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Juliana Dias
,
Stefan N. Tulich
, and
George N. Kiladis

1. Introduction Tropical deep convection is known to vary on a broad range of space and time scales. While a portion of this variability can be characterized as noise ( Wheeler and Kiladis 1999 , hereafter WK99 ), there are also coherent wavelike disturbances that can often be tracked for days or even weeks, implying a certain level of deterministic predictability (e.g., Waliser et al. 2003 ; Mapes et al. 2008 ). Such disturbances are of practical interest owing to their strong influence on

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Andrew J. Majda
and
Samuel N. Stechmann

listed above—from GCMs, simplified models, and everything in between—no theory for the MJO has yet been generally accepted, and the problem of explaining the MJO has been called the search for the Holy Grail of tropical atmospheric dynamics ( Raymond 2001 ). Building on earlier work, the present paper contributes to this search. While theory and simulation of the MJO remain difficult challenges, they are guided by the generally accepted, fundamental features of the MJO on intraseasonal

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