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Timothy W. Cronin

of 0.5 has been widely used. The early studies of radiative–convective equilibrium by Manabe and Strickler (1964) , Manabe and Wetherald (1967) , Ramanathan (1976) , and the early review paper by Ramanathan and Coakley (1978) all took . The daytime-average zenith angle has also been used in simulation of climate on other planets (e.g., Wordsworth et al. 2010 ) as well as estimation of global radiative forcing by clouds and aerosols ( Fu and Liou 1993 ; Zhang et al. 2013 ). To our

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Guoxing Chen, Wei-Chyung Wang, and Jen-Ping Chen

consistent with the biases found in the smaller simulated shortwave cloud radiative forcing in these regions ( Calisto et al. 2014 ; Flato et al. 2014 ). It is also known that these regions have been affected by aerosols emitted from the continents. For instance, the southeast Pacific (SEP), where the largest and most persistent stratocumulus deck in the world resides, is exposed to anthropogenic aerosols produced by copper smelters in South America ( Huneeus et al. 2006 ). The increased aerosols not

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Wojciech W. Grabowski

others. However, in nature, convective clouds continuously interact with their surroundings through gravity waves and detrainment that modify their environment (e.g., Bretherton and Smolarkiewicz 1989 ). These interactions affect development of subsequent clouds. Thus, it is irrelevant what the first cloud does, but what matters is a response of an ensemble of clouds to realistic forcings averaged over many cloud realizations. (An exception to this argument might be when the first cloud causes a

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Sunwook Park and Xiaoqing Wu

(2004) also examined the relationship between surface albedo and cloud radiative forcing (CF) over an Arctic region using the cloud and radiation dataset from the Surface Heat Budget of the Arctic (SHEBA) program. For middle latitude cases, some research groups have investigated various surface-albedo-related phenomena. Grant et al. (2000) examined the dependence of clear-sky albedo on the SZA by observing the daily variation of surface albedo at Uardry in southeastern Australia. Considering the

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Bingqi Yi, Ping Yang, Bryan A. Baum, Tristan L'Ecuyer, Lazaros Oreopoulos, Eli J. Mlawer, Andrew J. Heymsfield, and Kuo-Nan Liou

thickness using the SR ice particle model. Similar results were obtained for RRTMG but are not shown here. The CRE is highly sensitive to the changes in ice cloud optical thickness, while the dependence on D eff is weak. These results are in agreement with the study by Hong et al. (2009) . Fig . 2. (top) SW, (middle) LW, and (bottom) total cloud radiative forcing (CRF) at solar zenith angle (SZA) = 60° as a function of effective diameter and cloud optical thickness as simulated by the Fu–Liou RTM for

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Max Popp, Hauke Schmidt, and Jochem Marotzke

1. Introduction In the 1960s, the idea was advanced that, under strong radiative forcing, a runaway water vapor feedback may occur, which may lead to the evaporation of all oceans on an Earthlike planet (e.g., Gold 1964 ; Komabyashi 1967 ; Ingersoll 1969 )—the runaway greenhouse. The idea was used to explain how Venus could have lost most of its water and could have ended up with the inhospitable atmosphere that it has today. Even though 50 years have passed, the role of clouds in the

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Junyan Xiong, Jun Yang, and Ji Nie

branches of the meridional mean circulation ( Figs. 4b,c ). The midlatitude cloud belt is enhanced and shifts equatorward, consistent with the equatorward shift of the storm track ( Figs. 5b,c ). In the polar region, the cloud fraction decreases at all levels, consistent with the increased static stability associated with the subsidence of the polar cell ( Figs. 4b,c ). The responses of clouds induce positive shortwave radiative forcing in the subtropics and negative radiative forcing in the middle

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Joonsuk Lee, Ping Yang, Andrew E. Dessler, Bo-Cai Gao, and Steven Platnick

convective blowoff, whereas the other half were associated with in situ formation. Because of the high frequency of occurrence of thin cirrus clouds, the effect of these clouds on the earth’s radiation budget can be significant. For example, these clouds, located high in the atmosphere, absorb longwave radiation but emit radiation at very low temperatures, producing local heating by a few degrees per day ( Jensen et al. 1996 ; McFarquhar et al. 2000 ) and net positive cloud radiative forcing on the

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David B. Mechem, Yefim L. Kogan, Mikhail Ovtchinnikov, Anthony B. Davis, K. Franklin Evans, and Robert G. Ellingson

arising from MD effects may also influence convective dynamics. Instead of these predominantly indirect influences of MD radiative transfer (MDRT) on cloud dynamics, we are concerned with identifying direct impacts of MD effects on the cloud dynamics themselves. As such, we choose to focus on cloud types for which radiative forcing contributes significantly to the system energetics. For boundary layer stratocumulus, cloud top longwave radiational cooling is most frequently the primary engine driving

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Graeme L. Stephens and Peter J. Webster

1542~rOURNAL OF THE ATMOSPHERIC SCIENCESVOLUME 36Sensitivity of Radiative Forcing to Variable Cloud and Moisture GRAEME L. STEPHENS AND PETER J. WEBSTERCSIRO Division of Atmospheric Physics, Station Street, Aspendale, Victoria, Australia 3195(Manuscript received 1 November 1978, in final form 27 March 1979) ABSTRACT The influence of cloud and moisture distribution on the radiative forcing of the atmosphere is investigated.' A simple radiative transfer model is

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