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John G. Dwyer, Michela Biasutti, and Adam H. Sobel

simulation. While these differences prevent precise quantitative agreement between the coupled and uncoupled GCMs, the overall similarity of the results indicates that the uncoupled model is a useful tool for understanding the changes in the annual cycle in the coupled model. Next we investigate the effects that a spatially uniform mean temperature increase has on the seasonal characteristics of precipitation in the UW experiment. We increase the SST by 3 K ( Cess et al. 1990 ), a value almost identical

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Zewdu T. Segele, Michael B. Richman, Lance M. Leslie, and Peter J. Lamb

Barnston 2007 ). Also, because the effects of slowly evolving global SST variations on Ethiopian rainfall must be transmitted through changes in local and regional atmospheric circulations and SST patterns, development of monthly-to-seasonal Ethiopian rainfall predictions can be enhanced by identifying local and regional predictors and aggregating their effects into ensemble-based statistical prediction schemes. The present Kiremt predictability investigation involves 2–3-month lead time forecasts of

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Kerry H. Cook and Edward K. Vizy

1. Introduction Precipitation distributions over tropical East Africa exhibit pronounced regional variations, and the seasonal cycle is complicated. In most regions there are two peak rainfall seasons that are nominally associated with solar-heating maxima in the equinox seasons, but topography, SST forcing, and teleconnections to the West African and Indian monsoon systems are among the other important factors influencing the timing and intensity of seasonal rainfall. The tropical East African

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Gang Zhang, Kerry H. Cook, and Edward K. Vizy

) suggest that these delays are associated with inaccuracies in the model’s simulation of organized convective systems with radii less than 100 km. Dirmeyer et al. (2012) also show that a global convection-permitting model produces a more realistic diurnal cycle of rainfall than global models with parameterized convection or an embedded two-dimensional convection-permitting model. Convection-permitting simulations with GCMs are computationally expensive, especially for simulating seasonal or longer

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Peter J. Lamb, Diane H. Portis, and Abraham Zangvil

) the relationships between cumulus clouds and the soil–plant–atmosphere exchange of heat, carbon, and water at the SGP ACRF site; (iii) how land cover changes (including the winter wheat harvest) impact surface heat, carbon, and water fluxes, and whether those changes affect local and regional cumulus cloud formation at the SGP ACRF; (iv) how SGP land surface processes affect atmospheric aerosol loading and chemistry, and the resulting effects on cumulus cloud microphysics and macrophysics; and (v

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Lisa Hannak, Peter Knippertz, Andreas H. Fink, Anke Kniffka, and Gregor Pante

importantly precipitation over a large area. Monsoonal rainfall affects the livelihoods of hundreds of millions of people through its impacts on agriculture, health, water resources, and power generation. The large interannual to decadal variations of the WAM can have catastrophic consequences for the local population ( Benson and Clay 1998 ; Nicholson 2001 ). Therefore, a reliable weather, seasonal, and decadal climate prediction is crucial for many planning activities across the region. Despite these

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Gang Zhang, Kerry H. Cook, and Edward K. Vizy

models are expected to realistically capture the diurnal cycle of rainfall in the contemporary climate. However, previous studies (e.g., Cook and Vizy 2006 ; Dai 2006 ; Xue et al. 2010 ) show that the diurnal cycle of tropical rainfall is poorly simulated by the current generation of general circulation models (GCMs). Even when models produce realistic average rainfall amounts on seasonal time scales, they fail to correctly simulate the diurnal cycle of rainfall (e.g., Dai 2006 ). This deficiency

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Elinor R. Martin and Chris Thorncroft

. Figure 5 shows correlation values between JJAS EKE (at low and midlevels) and rainfall from all models, experiments, and all combinations of reanalysis and rainfall data as box-and-whisker diagrams. In observations, correlations are larger at 700 hPa, and all combinations of reanalysis EKE and observational rainfall are positive and significantly different from zero at a 95% significance level, indicating larger seasonal mean precipitation and increased EKE at 700 hPa. The spread is larger at 850

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Irenea L. Corporal-Lodangco, Lance M. Leslie, and Peter J. Lamb

-scale circulation associated with ENSO phases explains the relationship between ENSO and TC activity ( Chan 2000 ). Consequently, the emphasis in this study is on interseasonal (quarter years) time scales, reflecting the seasonal relationship between ENSO and Philippine TCs. Previous studies reveal significant differences in landfall rates in the northern Philippines between El Niño and La Niña events, with more intense typhoons making landfall in northern Luzon in La Niña years ( Saunders et al. 2000 ; Elsner

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Thomas Engel, Andreas H. Fink, Peter Knippertz, Gregor Pante, and Jan Bliefernicht

, Animation A2 ) and the fact that the development took place around the secondary early morning rainfall peak ( Sane et al. 2012 ) suggest that the land–sea breeze in the Cape Verde area contributed to the enhancement of convection and recurrent new cell generation. However, although the rain event was the most severe at the Dakar-Yoff station, its physical causes appear to be a coincidental combination of effects that are each frequently observable there. Fig . 8. As in Fig. 4 , but for the Dakar flood

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