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Timothy W. Cronin

1. Introduction Planetary albedo α exerts a fundamental control on climate. For certain atmospheric profiles, especially those with optically thin clouds, the planetary albedo decreases near linearly with the cosine of the solar zenith angle μ . That is to say, when the sun lies higher in the sky, a smaller fraction of sunlight is reflected than when the sun lies lower in the sky. Because of this covariance of albedo and solar zenith angle, choosing a simple time-mean solar zenith angle may

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Gregory P. Byrd and Stephen K. Cox

JANUARY 1984 GREGORY P. BYRD AND STEPHEN K. COX 173A Case Study of Radiative Forcing upon a Tropical Cloud Cluster System GREGORY P. BYRD! AND STEPHEN K. COXDepartment of Atmospheric Science, Colorado State University, Fort Collins, CO 80523(Manuscript received 11 August 1982, in final form 5 August 1983)ABSTRACT Tropospheric radiative convergence profiles from Cox and Griffith are used to assess the

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Zhanqing Li and Alexander P. Trishchenko

involve seven independent cloud variables acting on a hierarchy of spatial and temporal scales ( Wielicki et al. 1996 ). One aspect of the interaction can, however, be described by a single quantity, namely, the cloud radiative forcing (CRF) ( Charlock and Ramanathan 1985 ). A major advantage of using CRF is that its value can be obtained directly from satellite observation at the top of the atmosphere (TOA) ( Ramanathan et al. 1989 ; Harrison et al. 1990 ), as well as at the surface by means of

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Byung-Ju Sohn and Eric A. Smith

831AUGUST 1992SOHN AND SMITH(Manuscript received 15 January 1991, in final form 15 August 1991)ABSTRACTThe source and forcing mechanisms of radiation budget variability were examined over tropical latitudes byseparating the variations into cloud- and surface-forced components. A zonal harmonic analysis of emittedlongwave radiation emphasizes that these variations are largely controlled at the planetary wave scale. Positivetotal and cloud-forced longwave (LW) anomalies embedded within this

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Ming-Dah Chou and Wenzhong Zhao

squared meter of that estimated from TOGA COARE measurements. 5. Cloud radiative forcing The effect of clouds on radiative flux, or cloud radiative forcing (CRF), is defined as the difference between the all-sky flux and the clear-sky flux. The downward all-sky flux was measured at all the radiation stations. Due to some missing data, derivation of the daily flux for each day is not possible. Therefore, we first composite the diurnal variation of the surface flux from measurements for each of the four

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David A. Short, James E. Sardonia, Winifred C. Lambert, and Mark M. Wheeler

, westerly shear being correlated with severe weather ( Hagemeyer and Schmocker 1991 ). Easterly shear can also result in high-level anvil clouds over the space launch and landing facilities of the John F. Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) on Florida's east coast, originating from convective systems over the Atlantic Ocean. Caniaux et al. (1994) used the term “forward anvil clouds” to describe the westward-propagating anvil of a tropical squall line in easterly

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Paulo Ceppi and Dennis L. Hartmann

1. Introduction Clouds exert a very substantial effect on the energy balance of the earth’s atmosphere through their effects on shortwave (SW) and longwave (LW) radiation, with an approximate global-mean effect of −20 W m −2 ( Boucher et al. 2013 ). With increasing greenhouse gas forcing, the SW and LW radiative effects of clouds are expected to change, and while the magnitude of this change is highly uncertain, most climate models predict a positive global-mean forcing from cloud changes

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Baijun Tian and V. Ramanathan

1. Introduction A successful conceptual model for the tropical large-scale atmospheric circulation is that of Gill (1980) which proposed that the circulation is a linear response to atmospheric diabatic heating. Latent heating and atmospheric cloud radiative forcing (CRF) are the two major sources of diabatic heating for the tropical atmosphere ( Ramanathan 1987 ; Webster 1994 ). Atmospheric CRF is the difference between the radiative heating of the atmosphere for average cloudiness and that

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Richard W. Moore and Thomas H. Vonder Haar

1. Introduction Satellite-based observations of cloud–radiative flux interactions have been intensely studied over the past 25 years. Many different methods incorporating data from various satellite instruments have been used to quantify cloud forcing ( Arking 1991 ). There is agreement that clouds cool the earth, but estimates of the magnitude of cloud cooling vary depending on the method and dataset examined. Cloud forcing exhibits significant seasonal and geographic variability ( Harrison et

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Seoung Soo Lee

not on interactions between clouds and large scales much larger than the model domain where clouds are generated in this study. Hence, observed heat and moisture fluxes are imposed on the model surface and there are no two-way interactions between surface fluxes and clouds. To prevent the reflection of gravity or sound waves from the model top, a damping layer of 5-km depth is applied near the model top. The TWP-ICE observations provide initial humidity, temperature, and large-scale forcings of

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