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Paul A. Dirmeyer, Yan Jin, Bohar Singh, and Xiaoqin Yan

radiation over much of the United States and southern Canada has different manifestations in different areas. Across the core of the industrial belt around the Great Lakes, sensible heat is reduced and the cloud base drops. Farther south around the Ohio Valley, the boundary layer changes little despite the changes in surface heat flux. The central Great Plains is a particularly interesting region of change. The model consensus is that precipitation has decreased since preindustrial conditions, but

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Anji Seth, Sara A. Rauscher, Michela Biasutti, Alessandra Giannini, Suzana J. Camargo, and Maisa Rojas

(bottom up) mechanism controls the switch to increased precipitation during summer in most monsoon regions. During the spring/early summer transition from dry to wet conditions, evaporation and moisture flux convergence play critical roles toward the accumulation of boundary layer moisture. Regions where boundary layer moisture availability is reduced owing to decreases in evaporation and moisture convergence experience an enhanced convective barrier during early summer. Alternatively, regions

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Leila M. V. Carvalho and Charles Jones

by September. The onset of the rainy season over the Amazon is preceded by an increase in the frequency of the northerly cross-equatorial flow over South America that increases moisture in the boundary layer ( Marengo et al. 2001 , 2010 ; Wang and Fu 2002 ). The onset of the wet season in central and southeastern Brazil in the present climate typically occurs between September and November ( Silva and Carvalho 2007 ; Gan et al. 2004 ; Raia and Cavalcanti 2008 ). SAMS peaks from December

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Justin Sheffield, Suzana J. Camargo, Rong Fu, Qi Hu, Xianan Jiang, Nathaniel Johnson, Kristopher B. Karnauskas, Seon Tae Kim, Jim Kinter, Sanjiv Kumar, Baird Langenbrunner, Eric Maloney, Annarita Mariotti, Joyce E. Meyerson, J. David Neelin, Sumant Nigam, Zaitao Pan, Alfredo Ruiz-Barradas, Richard Seager, Yolande L. Serra, De-Zheng Sun, Chunzai Wang, Shang-Ping Xie, Jin-Yi Yu, Tao Zhang, and Ming Zhao

changes in SST boundary conditions across the CMIP5 standard-resolution models (Part III). Although not analyzed here, MIROC4h has a similar spatial resolution (0.56°) to C180-HIRAM. Evaluations by Sakamoto et al. (2012) show that MIROC4h can reproduce the global number of TCs, in part because of realistic SSTs, but severely underestimates the frequency in the North Atlantic, suggesting that higher model resolution is necessary but not sufficient to reproduce observed frequencies. Fig . 7. (top

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Eric D. Maloney, Suzana J. Camargo, Edmund Chang, Brian Colle, Rong Fu, Kerrie L. Geil, Qi Hu, Xianan Jiang, Nathaniel Johnson, Kristopher B. Karnauskas, James Kinter, Benjamin Kirtman, Sanjiv Kumar, Baird Langenbrunner, Kelly Lombardo, Lindsey N. Long, Annarita Mariotti, Joyce E. Meyerson, Kingtse C. Mo, J. David Neelin, Zaitao Pan, Richard Seager, Yolande Serra, Anji Seth, Justin Sheffield, Julienne Stroeve, Jeanne Thibeault, Shang-Ping Xie, Chunzai Wang, Bruce Wyman, and Ming Zhao

changes for all locations. Comparison to a similar ensemble of 16 CMIP3 models indicates that, while the large-scale pattern of precipitation increases at middle to high latitudes and precipitation decreases in the subtropics are similar between the two intercomparisons, one notable difference is that the boundary between these changes has shifted slightly south. This yields projected precipitation increases over parts of California in CMIP5, passing the binomial test for agreement on sign at levels

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Justin Sheffield, Andrew P. Barrett, Brian Colle, D. Nelun Fernando, Rong Fu, Kerrie L. Geil, Qi Hu, Jim Kinter, Sanjiv Kumar, Baird Langenbrunner, Kelly Lombardo, Lindsey N. Long, Eric Maloney, Annarita Mariotti, Joyce E. Meyerson, Kingtse C. Mo, J. David Neelin, Sumant Nigam, Zaitao Pan, Tong Ren, Alfredo Ruiz-Barradas, Yolande L. Serra, Anji Seth, Jeanne M. Thibeault, Julienne C. Stroeve, Ze Yang, and Lei Yin

decadal climate predictability and why models give different answers when driven by the same forcings. The CMIP5 builds on the previous phase (CMIP3) experiments in several ways. First, a greater number of modeling centers and models have participated. Second, the models generally run at higher spatial resolution with some models being more comprehensive in terms of the processes that they represent, therefore hopefully resulting in better skill in representing current climate conditions and reducing

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Kerrie L. Geil, Yolande L. Serra, and Xubin Zeng

and found that the model's enhanced representation of the surface boundary produced an acceptable diurnal cycle of summer precipitation in the monsoon region that was not captured by the driving reanalysis. A recent study by the same group using the Weather Research and Forecasting Model (WRF; Castro et al. 2012 ) showed the potential for limited-area models to improve seasonal NAMS forecasts. The use of higher resolution limited-area models that are able to capture the diurnal cycle of

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Baird Langenbrunner and J. David Neelin

: Role of boundary conditions and model formulation in two GCMs . Climate Dyn. , 25 , 709 – 723 . Chen , W. Y. , and H. M. van den Dool , 1997 : Asymmetric impact of tropical SST anomalies on atmospheric internal variability over the North Pacific . J. Atmos. Sci. , 54 , 725 – 740 . Chiang , J. C. H. , and A. H. Sobel , 2002 : Tropical tropospheric temperature variations caused by ENSO and their influence on the remote tropical climate . J. Climate , 15 , 2616 – 2631 . Chou , C

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Suzana J. Camargo

interesting to note that the MRI-CGCM3 SST is too warm in the Southern Hemisphere, where the model’s GPI is high and the model produces too many TCs. A few models have warm SST anomalies in the western boundaries of the American continent. Various studies showed that future TC projections are sensitive to the specific SST patterns in the models ( VS07b ; Sugi et al. 2009 ; Villarini et al. 2011 ). However, similar to GPI, the direct relationship of TC frequency and SST bias is not enough to explain the

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