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Piero Cau, John Methven, and Brian Hoskins

, approximately independent of layer altitude. Such sensitivity implies that the distribution of humidity can have a significant role in the response of the Tropics in a climate-change scenario. Since specific humidity is conserved following an air mass in the absence of phase changes or mixing, its humidity is determined at the instant when condensation last occurred (assuming weak mixing and that the reevaporation of condensate is not important). The mixing ratio set by the condensation event depends on

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Ian Folkins, S. Fueglistaler, G. Lesins, and T. Mitovski

1. Introduction In the tropics, convective clouds are often considered to fall into one of three categories: boundary layer, shallow, or deep ( Johnson et al. 1999 ). Boundary layer convective clouds contribute to an upward eddy flux of heat and moisture from the surface, are usually nonprecipitating, and rarely penetrate the 2-km local maximum in static stability. Most of the rainfall in the tropics is associated with deep cumulonimbus and stratiform clouds, whose outflow is preferentially

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Alison M. Anders and Stephen W. Nesbitt

1. Introduction Large spatial gradients in precipitation are common in mountains (e.g., Anders et al. 2006 , 2007 ; Prat and Barros 2010 ; Giambelluca et al. 2013 ) and relevant to diverse fields including hydrology, climatology, hazards assessment, and geomorphology. In the midlatitudes, precipitation rates typically increase with elevation on windward-facing slopes, consistent with stable upslope flow driving progressive rainout ( Sawyer 1956 ; Smith 1979 ; Roe 2005 ). In the tropics

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Nedjeljka Žagar, Ad Stoffelen, Gert-Jan Marseille, Christophe Accadia, and Peter Schlüssel

1. Introduction A lack of direct observations of wind profile measurements over a significant part of the earth has been recognized as the main missing component of the current operational observing system (e.g., Baker et al. 1995 ; World Meteorological Organization 2000 ). The problem is most severe in the tropics, where wind field information is also more important than mass information for the atmospheric dynamics and initialization of the numerical weather prediction (NWP) models (e

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Xiping Zeng, Wei-Kuo Tao, Toshihisa Matsui, Shaocheng Xie, Stephen Lang, Minghua Zhang, David O’C Starr, and Xiaowen Li

, have been observed to be more frequent in the tropics than in middle latitudes (e.g., Heymsfield et al. 1978 ; Wei et al. 1998 ; Igau et al. 1999 ). Zipser (2003) , after reviewing the aircraft observations from over the past decades, concluded that undilute updraft cores have not been found in the tropics but are common in severe storms in middle latitudes. Based on this meridional variation in fine cloud dynamic structure, it is inferred that the IE factor in the tropics is much larger than

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Kazuyoshi Kikuchi and Bin Wang

so far in the global tropics. The purpose of this study is to construct a reference of the climatological diurnal precipitation in the global tropics using nine years of Tropical Rainfall Measuring Mission (TRMM) data and empirical orthogonal function (EOF) analysis. This work will not only provide a metric for evaluating global numerical models’ performance but also broaden our knowledge and shed some light on the mechanism at work. The TRMM data provide us this opportunity to study the

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Robin Chadwick, Ian Boutle, and Gill Martin

changes in net tropospheric radiative cooling and latent heating ( Lambert and Webb 2008 ). However, the level of agreement between GCMs on regional precipitation changes is low throughout large areas of the tropics, with even the sign of change uncertain for many regions ( Meehl et al. 2007 ; Rowell 2012 ). Therefore, the mechanisms that lie behind the spatial patterns of the tropical rainfall response to climate change are of great interest. The aim of this study is to investigate these mechanisms

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Shoshiro Minobe, Jun Hyock Park, and Katrina S. Virts

region ( Minobe and Takebayashi 2015 ; Virts et al. 2015 ). These western boundary currents transport warm water from the tropics poleward, resulting in sea surface temperatures (SSTs) warmer than 26°C, the threshold of deep convection over the ocean under the current climate ( Graham and Barnett 1987 ; Waliser et al. 1993 ). The warm SST allows tropical-like atmospheric convection associated with the air–sea interaction with these currents ( Minobe et al. 2008 ; Minobe et al. 2010 ; Sasaki et al

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T. N. Krishnamurti, C. Gnanaseelan, A. K. Mishra, and A. Chakraborty

Sanjay 2003 ). It is possible to use these weights and construct a single forecast model that uses a weighted average (based on these weights) for a unified model. Such a unified model was shown to carry a skill higher than those of the member models and their ensemble mean but lower than a multimodel superensemble. These results are shown in Figs. 1 and 2 for days 1 and 2 of rainfall forecasts over the global tropics, North America, and the Asian monsoon domain. In a related study, Chakraborty

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Hye-Yeong Chun, Jung-Suk Goh, In-Sun Song, and Lucrezia Ricciardulli

( c ) were carried out. It was found that on a global scale in the Tropics DCH has a dominant period of 1 day and a zonal wavelength of about 1600 km. The phase-speed spectrum of DCH is Gaussian type and its power decreases rapidly as phase speed increases from the maximal value at c = 0. This convective source spectrum is similar to that proposed by Beres et al. (2004) and SC05 for the cloud-top momentum flux formulations of convective GWD parameterizations. Two-dimensional ( k − ω

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