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David K. Adams, Rui M. S. Fernandes, Kirk L. Holub, Seth I. Gutman, Henrique M. J. Barbosa, Luiz A. T. Machado, Alan J. P. Calheiros, Richard A. Bennett, E. Robert Kursinski, Luiz F. Sapucci, Charles DeMets, Glayson F. B. Chagas, Ave Arellano, Naziano Filizola, Alciélio A. Amorim Rocha, Rosimeire Araújo Silva, Lilia M. F. Assunção, Glauber G. Cirino, Theotonio Pauliquevis, Bruno T. T. Portela, André Sá, Jeanne M. de Sousa, and Ludmila M. S. Tanaka

The Amazon Dense GNSS Meteorological Network provides high spatiotemporal resolution, all-weather precipitable water vapor for studying the evolution of continental tropical and sea-breeze convective regimes of Amazonia. The meteorology and climate of the equatorial tropics are dominated by atmospheric convection, which presents a rather challenging range of spatial and temporal scales to capture with present-day observational platforms ( Mapes and Neale 2011 ; Moncrieff et al. 2012 ; Zhang

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Byung-Ju Sohn and Johannes Schmetz

mean upper-tropospheric humidity and large-scale divergence. More recently, by separating the tropical area into moist cloudy, moist clear, and dry areas, Lindzen et al. (2001 , hereafter LCH) studied impact of water vapor redistribution owing to relative changes in the fractional areas of cloudy/moist regions in the Tropics on the radiation energy balance. Although their result regarding so-called “infrared adaptive iris” hypothesis turned out to be very controversial and has been refuted (e

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Hirohiko Masunaga and Brian E. Mapes

1. Introduction Early modern theories of the Hadley circulation ( Schneider and Lindzen 1977 ; Schneider 1977 ; Held and Hou 1980 ) were built largely around dry dynamics, with moist processes viewed as secondary or implicit. In the typical cartoon, deep convection is sketched in the ascending branch, with shallow cumuli at the bottom of the descending branch. This schematic view is silent about water vapor. While precipitation needs to prevail in the tropics to balance column moisture

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Sarah M. Kang, Dargan M. W. Frierson, and Isaac M. Held

). It is, thus, worthwhile to use intermediate complexity models that ignore cloud radiative feedbacks to better understand the changes in atmospheric energy transport and the connection between these changes in transport and the tropical precipitation. For instance, clouds being able to create significant gradients in the energy balance at the top of the tropical atmosphere, which would otherwise be small as a consequence of the small temperature gradients in the tropics, can mask the fundamental

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Jian Yuan, Dennis L. Hartmann, and Robert Wood

longwave radiation (OLR) when compared to clear skies ( Ramanathan et al. 1989 ; Harrison et al. 1990 ). In the tropics (30°N–30°S) clouds increase TRS by 45 W m −2 and reduce OLR by 33 W m −2 , yielding a total reduction in the net radiation of 12 W m −2 , so that the effect of clouds on the tropical energy balance is less negative than on the global average, largely as a result of the presence of high, cold clouds in the tropics. The cloud effects on the radiative energy balance, which are often

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Tadashi Tsuyuki

parameterization schemes. However, Zou et al. (1993b) demonstrated the ability to perform 4D-VAR with discontinuous physical processes. D. Zupanski (1993) showed that the adverse effects of discontinuities in a cumulus convection scheme can be reduced by modifying the scheme to make it more continuous. Their results encouraged development of 4D-VAR with physical processes and its application to tropical data analysis. The major advantage of 4D-VAR in the Tropics is the use of full model dynamics to

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Sara A. Rauscher, Xiaoyan Jiang, Allison Steiner, A. Park Williams, D. Michael Cai, and Nathan G. McDowell

accelerate through the reduction of the biomass carbon sink. As a result of the interplay between the two effects of CO 2 , the fertilization effect and climate change itself, it is unclear how future climate and vegetation trajectories will unfold. In the tropics, the relative importance of two competing climate responses to increasing greenhouse gases 1 —a local (“bottom up”) response and a remote (“top down”) response ( Giannini 2010 ; Seth et al. 2011 , 2013 )—is likely an important arbiter of how

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Leila M. V. Carvalho, Charles Jones, and Tércio Ambrizzi

[December–January–February (DJF)] with the objective to address the following questions: 1) Are distinct AAO phases related to the variability of convection and circulation in the Tropics caused by interannual variation phenomena such as El Niño/La Niña? 2) On intraseasonal time scales are there variations of circulation in the Tropics and subtropics related to distinct phases of the AAO? 3) Can tropical anomalies such as the MJO play a role in modulating phases of the AAO? 4) How does the extratropical

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Charles Jones and Jimy Dudhia

predictability in the tropics and extratropics of both hemispheres ( Waliser et al. 2003 ; Jones et al. 2004a , b ; Gottschalck et al. 2010 , 2013 ). Therefore, studies in the 1990s realized the importance of determining the skill of operational numerical weather prediction models in forecasting the MJO ( Chen and Alpert 1990 ; Lau and Chang 1992 ). However, global models at the time were not able to maintain the convectively coupled structure of the MJO, and forecast skill of the MJO was limited to

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Nicholas M. J. Hall, Hervé Douville, and Laurent Li

1. Introduction Information emanating from the tropics has long been considered a potential source of improvement for predictions in the extratropics. Rossby waves generated by the response to tropical convective heating present a well-known mechanism for tropical influence on the midlatitudes. Much of the early literature on this subject is centered around sea surface temperature anomalies especially in the tropical Pacific [see Trenberth et al. (1998) for a review]. In recent years

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