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cloud-producingcirculation features. These biases appear to be smallest in the Tropics and, consequently, the winds here can be veryuseful for studies of the average circulation at low latitudes. Some of the important features of this circulation overthe equatorial Pacific are clearly revealed.1. INTRODUCTIONThe purpose of this note is to present and evaluatesome preliminary computations of resultant winds overthe Pacific Ocean as deduced from ATS 1 cloud motionsfor November 1969. ATS 1 is a

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Murry L. Salby and Patrick F. Callaghan

wintertime troposphere. Over the Arctic, they appear conspicuously in anomalous temperature and height. Those changes of wintertime structure are shown here to be accompanied by changes of summertime structure over the Southern Hemisphere. Operating coherently with both are changes in the Tropics, even inside the tropical troposphere. Analogous changes are found in total ozone. In records over the 1980s and 1990s, we explore interannual changes in the Tropics and summer hemisphere that operate coherently

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S-K. Kao and R. J. Kuczek

308 JOURNAL OF THE ATMOSPHERIC SCIENCES VOLU.~!E30NOTES AND CORRESPONDENCEThe Kinetic Energy of Large-Scale Atmospheric Motionin Wavenumber-Frequency Space: IlL The Tropics S.-K. K~,o~National Center for A tmospheric Research? Botdder, Colo. 80302^ND R. J. Kucz~KDept. of Meteorology, University o.[ Utah, Salt Lake City 84112 15 September 1972 and 24 November 1972

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E. Palmén, Herbert Riehl, and L. A. Vuorela

, centerednear 200 mb, has about the same speed. An inactive layer without much net poleward or equatorward component extends from 700 to 400 mb.Next, the release of kinetic energy by the meridional circulation is calculated, and it is shown that thisrelease equals the kinetic energy export from the tropics to the middle latitudes. Finally, the mean meridionalcirculation exports heat from the tropics poleward; at 15 deg lat this heat transport has the right order ofmagnitude to balance the net heat loss in

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Masakazu Taguchi

colder in an experiment for a NH winter-like situation when the convective heating placed on the equator forces equatorial Rossby waves in the deep tropics, thus inducing stronger equatorial upwelling. When the heating is placed off the equator at 15°N to mimic a NH summerlike condition, the response is characterized by a dominant monsoon pattern in the subtropics. In contrast, a further observational analysis by Randel et al. (2008) using the National Centers of Environmental Prediction (NCEP

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Hella Garny, Martin Dameris, William Randel, Greg E. Bodeker, and Rudolf Deckert

trace gases with tropospheric sources therefore depend on the strength of the upwelling ( Holton et al. 1995 ). Because changes in tropical upwelling can induce trends in stratospheric composition, it is important to understand how tropical upwelling might be influenced by changes in climate. Upwelling in the tropics, forced by extratropical waves, constitutes the equatorial branch of the BDC ( Holton et al. 1995 ; Haynes et al. 1991 ). However, extratropical wave forcing alone cannot account for

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Zhengzhao Luo, Dieter Kley, Richard H. Johnson, and Herman Smit

van Velthoven (1997) and Ovarlez et al. (2000) focused on the modes (i.e., dry and moist conditions) whereas Oikonomou and O’Neill (2006) looked at the means. Since UTWV often shows bimodal distribution ( Zhang et al. 2003 ; Part I ), especially over the tropics, the bulk mean usually lies between the two modes. Similar means can be obtained through very different combinations of the modes. A more desirable approach would therefore be to study entire probability density functions (PDFs

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Fiaz Ahmed and J. David Neelin

studies. For instance, recent works ( Hannah et al. 2016 ; Allen and Mapes 2017 ) have suggested that the Lagrangian tracking of the CWV field can aid in interpreting salient synoptic variations in the tropics. Another avenue of research, directly relevant to this study, is the question of entrainment, which can be found in the earliest treatises on the subject ( Austin 1948 ; Houghton and Cramer 1951 ; Morton et al. 1956 ; Asai and Kasahara 1967 ). A satisfactory understanding and modeling of

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Salil Mahajan, R. Saravanan, and Ping Chang

1. Introduction Recently, interest has grown over the possibility of higher-latitude climate change forcings impacting the tropics. Studies have particularly focused on the impacts of high-latitude cooling on the tropics, such as that associated with the Last Glacial Maximum (LGM) and Heinrich events, when the Atlantic meridional overturning circulation (AMOC) is believed to be weaker than the current state (e.g., Manabe and Broccoli 1985 ; Broccoli 2000 ; Chiang et al. 2003 ; Chiang and

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Michael Ghil and Kingtse Mo

752 JOURNAL OF THE ATMOSPHERIC SCIENCES VOL. 48, No. 5Intraseasonal Oscillations in the Global Atmosphere.Part I: Northern Hemisphere and Tropics MICHAEL GHILClimate Dynamics Center, Department of Atmospheric Sciences, and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California KINGTSE MOClimate Analysis Center

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