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F. Parol, J. C. Buriez, G. Brogniez, and Y. Fouquart

). Thick highclouds appear as light shade against a dark ocean background invisible and infrared images. Semitransparent cirrus clouds appear aslight shades while thick clouds appear as black ones against the relatively dark cloud-free background in (c). The small area outlinedin white is the area used for the bidimensional plot shown on Fig. 2.section, we further investigate the relationship betweenthe BTD and the cloud optical properties and microphysics. For this analysis, the atmosphere is

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Jason A. Otkin, Thomas J. Greenwald, Justin Sieglaff, and Hung-Lung Huang

calculation for each SEVIRI infrared channel involves several steps within the forward modeling system. First, “CompactOPTRAN,” which is part of the National Oceanic and Atmospheric Administration Community Radiative Transfer Model (CRTM), is used to compute gas optical depths for each model layer from the WRF-simulated temperature and water vapor mixing ratio profiles and climatological ozone data. Ice cloud absorption and scattering properties, such as extinction efficiency, single-scatter albedo, and

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Galina Wind, Steven Platnick, Michael D. King, Paul A. Hubanks, Michael J. Pavolonis, Andrew K. Heidinger, Ping Yang, and Bryan A. Baum

1. Introduction Plane-parallel single-layered cloud radiative transfer (RT) models are used by global passive imager algorithms like Moderate Resolution Imaging Spectroradiometer (MODIS) ( Barnes et al. 1998 ) for cloud thermodynamic phase, cloud-top pressure–temperature, and optical and microphysical properties retrievals ( King et al. 2003 ; Platnick et al. 2003 ). The use of such an RT model works reasonably well, as confirmed by many field campaigns and theoretical calculations ( King et

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Jun Li, W. Paul Menzel, Wenjian Zhang, Fengying Sun, Timothy J. Schmit, James J. Gurka, and Elisabeth Weisz

. The cloud microphysical properties are described in terms of cloud particle size (CPS) in diameter and visible cloud optical thickness (COT). Given the visible COT and CPS, the IR COT, single-scattering albedo, and asymmetry factor can be parameterized for radiative effects of ice clouds and water clouds. The cloudy radiance for a given AIRS channel can be calculated by combining the clear-sky optical thickness from SARTA and the cloud effects by adding a COT, single-scattering albedo, and

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Patrick Minnis, Patrick W. Heck, David F. Young, C. W. Fairall, and J. B. Snider

VOLUME31surface. The surface albedo in the radiative transfermodel isOfsfc = 2.8(/~'s + 0.065) + 15(ix0 - 0.][) + (~o -- 0.5)(#0 - 1),which is a variation on the parameterization of Brieglebet al. (1986). The lowest layer in the model is a pureRayleigh-sdattering layer having an optical depth corresponding to a thickness of 75 mb. The second layeris a plane-parallel cloud of varying optical depth, andthe cloud optical properties are determined from Miecalculations using the program

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Thorwald H. M. Stein, Julien Delanoë, and Robin J. Hogan

sensitivities ( Waliser et al. 2009 ). The A-Train constellation of satellites takes various measurements of ice clouds ( Stephens et al. 2002 ). It started with the launch of Aqua in 2002, carrying the Moderate Resolution Imaging Spectroradiometer (MODIS), which retrieves cloud optical properties using shortwave and infrared radiances. In 2006, Aqua was joined by CloudSat and the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations ( CALIPSO ) ( Winker et al. 2003 ), providing

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C. Prabhakara, R. S. Fraser, G. Dalu, Man-Li C. Wu, R. J. Curran, and T. Styles

1987)ABSTRACT Spectral differences in the extinction between the 10.8 and 12.6 ~m bands of the infrared window region,due to optically thin clouds, are observed in the measurements made by a broad-band infrared aircraft radiometer.Similar spectral properties are also revealed by the measurements made by the high-resolution infrared interferometer spectrometer (IRIS) aboard the Nimbus-4 satellite, which had a field of view of ~95 km. Theseobservations show that the extinction due to cloud

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Stephen H. Schneider and Robert E. Dickinson

climate models are given and are shown tobe limiting cases of a more general formula. Since this more general formula depends on the spatial distribution of subgrid-scale cloud cover amounts, an unambiguous definition of cloud amount over a GCM-scale gridsquare cannot be given, even if perfect knowledge of the optical properties of the subgrld-scale clouds werein hand. However, the uncertainties in downward solar flux at the earth's surface or the albedo of thecombined cloudiness-surface system

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Michael J. Pavolonis and Jeffrey R. Key

high southern latitudes as compared with other regions of the world. Cloud cover and cloud optical properties will greatly influence the surface radiation budget. For example, Hines et al. (1999) found that the downwelling longwave flux at the surface was up to 50 W m −2 too small in National Centers for Environmental Prediction (NCEP) Medium-Range Forecast (MRF) model simulations over the Antarctic because of lower cloud amounts. The mere presence of clouds can greatly alter the downwelling

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G. S. Kent, F. Köpp, and Ch Werner

)ABSTRACT Remote sensing of the lower atmosphere by lidar yields profiles of the backscattering cross sectionalong the optical path. These may be simply converted to give a qualitative picture of the distributionof atmospheric aerosol, but quantitative values can only be obtained if further information is availableon aerosol properties such as refractive index and size distribution. In the experiments described below,use was made of a solar radiometer to give information on the second of these. This

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