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R. M. Welch and B. A. Wielicki

the calculation of radiative reflected fluxes from astratocumulus cloud field. The scheme is based upon plane-parallel calculations, such as delta-Eddington, anda simple procedure is outlined by which the plane-parallel fluxes may be transformed to those of the brokencloud case. This porameterization scheme has been tested for optical thicknesses ranging from r = 3 to 49, solarzenith angles ranging from ~0 = 0- to 72.5-, and all values ofcloud cover. Plane-parallel calculations becomeincreasingly

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Surabi Menon, Anthony D. Del Genio, Dorothy Koch, and George Tselioudis

measure of the radiative impact of aerosols on clouds. Furthermore, global climatologies of aerosol properties exist only over ocean, provide only the column optical thickness, do not differentiate among aerosol types, and have large uncertainties due to contamination by thin clouds ( Stowe et al. 1997 ). Thus, the only way to estimate the global AIE is by combining model simulations with satellite observational constraints (cf. Boucher 1995 ; Kogan et al. 1997 ). Unfortunately, existing general

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Xiang Li, Sundar A. Christopher, Joyce Chou, and Ronald M. Welch

—Brazil (SCAR-B) experiment ( Kaufman et al. 1998 ). The calculated smoke ADM is a function of aerosol optical properties, surface albedo, and solar and satellite viewing geometry. Using the visible and infrared scanner (VIRS) imagery, smoke pixels are detected, and the optical thickness of the detected smoke pixels is retrieved. The TOA SW fluxes for smoke aerosols are obtained using the measured CERES radiances and the calculated ADMs for smoke aerosols. Then, we compare the calculated TOA SW fluxes for

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Hyoun-Myoung Cho, Shaima L. Nasiri, Ping Yang, Istvan Laszlo, and Xuepeng “Tom” Zhao

satellite. Note that the reflectances in the solar bands have been solar zenith angle corrected and the brightness temperatures have been converted from radiances. The level-2 MODIS aerosol product (MYD04) retrievals of aerosol optical thickness (AOT) at 0.55 μ m using the dark target approach ( Remer et al. 2005 ) are used when comparing dust detection results. b. CALIPSO cloud and aerosol layer product The CALIPSO cloud and aerosol products used in this study are from the CALIPSO 5-km level-2

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Francesca Barnaba and Gian Paolo Gobbi

been shown (e.g., Kovalev 1995 ) that this assumption can lead to inaccurate estimates of the aerosol extinction, particularly when employed in turbid, nonhomogeneous, that is, real atmospheres. For example, analysis of the LITE measurements in Saharan dust conditions performed assuming two (boundary) values for the lidar ratio, R eb = 25 sr and R eb = 35 sr, led to maximum aerosol optical thickness AOT = 0.66 and AOT > 1, respectively ( Karyampudi et al. 1999 ). This example shows how crucial

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Chenxi Wang, Ping Yang, Bryan A. Baum, Steven Platnick, Andrew K. Heidinger, Yongxiang Hu, and Robert E. Holz

1. Introduction Numerous approaches (e.g., Nakajima and King 1990 ; Stubenrauch et al. 1999 ; Platnick et al. 2003 ; Chiriaco et al. 2004 ; Kokhanovsky and Nauss 2005 ; Minnis et al. 2011a , b ) have been developed to infer ice cloud optical thickness τ , effective particle size D eff , and the ice particle size distribution function (PSD; e.g., Mitchell et al. 2010 ) from satellite-based imager and hyperspectral infrared (IR) sounder measurements. The method used by the Moderate

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Dietrich Althausen, Detlef Müller, Albert Ansmann, Ulla Wandinger, Helgard Hube, Ernst Clauder, and Steffen Zörner

J. P. Meyzonette, Eds., Proc. SPIE, 1714, 209–219 . 10.1117/12.138527 Leiterer, U., A. Naebert, T. Naebert, and G. Alekseeva, 1995: A new star photometer developed for spectral aerosol optical thickness measurements in Lindenberg. Contrib. Atmos. Phys., 68, 133–141 . Makiyenko, E. V., and I. E. Naats, 1983: Determination of the optical properties of the stratospheric aerosols by multifrequency laser sensing. Izv. Atmos. Oceanic Phys., 19, 748–751 . McCormick, P., 1982: Lidar

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Andréa Dde Almeida Castanho, Paulo Artaxo, J. Vanderlei Martins, Peter V. Hobbs, Lorraine Remer, Marcia Yamasoe, and Peter R. Colarco

the particles were measured as a function of the aircraft altitude and location. Spectral aerosol optical thickness and particle volume size distribution were derived from sun photometer measurements located at Wallops and at COVE. The sun photometers were automatic sun-/sky-scanning radiometers and part of AERONET, which is distributed throughout the world ( Holben et al. 1998 ). Principal factor analyses (PFA) were used to identify the sources of pollutants ( Thurston and Spengler 1985 ). The

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Ralph Kahn, Wen-Hao Li, John V. Martonchik, Carol J. Bruegge, David J. Diner, Barbara J. Gaitley, Wedad Abdou, Oleg Dubovik, Brent Holben, Alexander Smirnov, Zhonghai Jin, and Dennis Clark

1. Introduction The importance of retrieving aerosol optical thickness (AOT) and aerosol properties over dark water first drew attention when it was recognized that mineral dust from source regions in the Sahara Desert is regularly transported across the Atlantic Ocean and deposited in the Caribbean (reviewed by Prospero et al. 1983 ). Subsequent measurements identified significant transoceanic material redistribution of Asian dust and pollution as well (e.g., Clarke et al. 2001 ; Gao et al

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Alexander Ignatov

case, the upward radiance depends mainly on the aerosol optical thickness δ A and the aerosol single scattering phase function P A ( χ ), χ being scattering angle. Retrieval of δ A SAT from satellite over oceans was proposed by Griggs (1983) . In this case, P A ( χ ) has to be prescribed, as was realized, for example, in the algorithm of Rao et al. (1989) , which uses measurements in channel 1 (0.63 μ m) of the Advanced Very High Resolution Radiometer (AVHRR) onboard National Oceanic and

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