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S. J. Ghan, X. Liu, R. C. Easter, R. Zaveri, P. J. Rasch, J.-H. Yoon, and B. Eaton

indirect and semidirect forcing. With the exception of the direct forcing, all other forcing distributions vary widely between regions, from regional cooling exceeding 10 W m −2 to warming exceeding 5 W m −2 . Semidirect effects are statistically insignificant almost everywhere, while there is a tendency for compensation between shortwave and longwave indirect forcing. Much of the spatial variability in shortwave indirect forcing is associated with spatial variability in changes in liquid water path

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Samuel Levis, Gordon B. Bonan, Erik Kluzek, Peter E. Thornton, Andrew Jones, William J. Sacks, and Christopher J. Kucharik

yields for a range of nutrient and water availabilities and weather conditions at local to regional scales (e.g., Hodges et al. 1987 ). Climate scientists first used crop models to simulate the effects of climate change on crops (e.g., Mearns et al. 1999 ). Such studies neglected potential two-way climate–crop interactions, so Tsvetsinskaya et al. (2001a , b ) coupled a regional climate model to a crop model in a proof-of-concept exploration of climate–crop interactions over the central Great

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Susan C. Bates, Baylor Fox-Kemper, Steven R. Jayne, William G. Large, Samantha Stevenson, and Stephen G. Yeager

global, net air–sea fluxes of heat and freshwater are near zero ( Large and Yeager 2009 ) and much smaller than the uncertainty in observational estimates. However, significant climate trends can be sustained by small imbalances in the air–sea heat fluxes and the freshwater fluxes into the ocean. The evaporation of water from the ocean determines the strength of the earth’s hydrological cycle, and the climate effects of imbalance with the surface water fluxes of precipitation and runoff are changes

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Matthew C. Long, Keith Lindsay, Synte Peacock, J. Keith Moore, and Scott C. Doney

-state balance with the preindustrial atmosphere. Anthropogenic CO 2 (C ant ) is the additional carbon absorbed by the ocean because of the atmospheric CO 2 transient. We compute fluxes and inventories of C ant by subtracting simulated fields in the control integrations (CORE1850 and CPLD1850) from those in the respective transient integrations (CORE20C and CPLD20C). The control integrations include twentieth-century climate change (see above); thus, the climate effects on C nat distributions are present

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A. Gettelman, J. E. Kay, and J. T. Fasullo

). There is strong regional cancellation between the SW ( Figs. 3a , 4a ) and the LW ( Figs. 3b , 4b ). The anticorrelation occurs in the same regions (especially the storm tracks), indicating reductions in clouds with SW and LW effects on the equatorward branches of the storm tracks. Stratocumulus transition regions off the eastern coasts of South America, Africa, and North America also show up without LW effects, indicating low stratus clouds. However, their area is small. The transition regions do

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Laura Landrum, Bette L. Otto-Bliesner, Eugene R. Wahl, Andrew Conley, Peter J. Lawrence, Nan Rosenbloom, and Haiyan Teng

the tropical Pacific with impacts on worldwide seasonal weather. It is evident as the leading-order EOF of monthly sea surface temperature ( Deser et al. 2012 ). The regional effects of ENSO, which tend to be opposite between El Niño (the warm phase) and La Niña (the cool phase) include droughts/floods in the western Pacific, increased/decreased rainfall in the southwest United States and Peru, weaker/stronger Indian monsoons, and warmer/cooler temperatures in northwestern North America. ENSO

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A. Gettelman, J. E. Kay, and K. M. Shell

greenhouse effect due to water vapor (the water vapor feedback). Melting of snow or sea ice lowers the surface albedo, resulting in more absorption of solar radiation (the surface albedo feedback). Increases in surface and atmospheric temperature cause more emission to space, a cooling effect (temperature feedbacks). Clouds exert complex feedbacks due to their opposite shortwave and longwave effects. Clouds reflect shortwave radiation to space, cooling the planet, but absorb longwave radiation and emit

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Marika M. Holland, David A. Bailey, Bruce P. Briegleb, Bonnie Light, and Elizabeth Hunke

evolution, and fall freeze-up. Accounting for these phases in numerical models requires a parameterization of melt pond effects. Melt ponds are primarily formed by the accumulation of surface meltwater from snow and ice. Their shape, size, and coverage are determined by a number of factors including the total amount of water available and the ice surface topography. Several field experiments in combination with satellite observations have provided information on the characteristics of Arctic melt ponds

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Gerald A. Meehl, Warren M. Washington, Julie M. Arblaster, Aixue Hu, Haiyan Teng, Jennifer E. Kay, Andrew Gettelman, David M. Lawrence, Benjamin M. Sanderson, and Warren G. Strand

these cloud drops. Since one of the criticisms of CCSM4 was that it did not include the aerosol indirect effect, its inclusion in CESM1(CAM5) represents a major improvement. Another improvement that provides more realism is that there is time-evolving land use change in the twentieth- and twenty-first-century climate simulations ( Lawrence et al. 2011 ). Those land use changes were shown by P. J. Lawrence et al. (2012) to not have large global effects, but to affect some regional climate regimes

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Esther C. Brady, Bette L. Otto-Bliesner, Jennifer E. Kay, and Nan Rosenbloom

-term control, twentieth-century, and future projection simulations, which also prescribe these forcings. Although the vegetation biogeography did not change in our LGM simulation, the phenology response to the LGM climate is included. Prediction of aerosols and vegetation will be included in Community Earth System Model (CESM) LGM simulations and are expected to have important regional effects. The PMIP3/CMIP5 LGM ice sheet reconstruction is a blended product obtained by averaging three different ice sheet

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