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Shashi K. Gupta

computing downward, upward, and net longwave radiation atthe earth's surface using meteorological data from NOAA's operational sun-synchronous satellites. The parameterization was developed using a narrowband radiative transfer model and a large meteorological databaseconsisting of satellite and in situ soundings. Clear-sky downward flux was represented as a function of surfaceand lower tropospheric temperatures, and water vapor burden of the atmosphere. Cloud contribution to thedownward flux was

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Mino-Dah Chou

calculations. With informationavailable from many climate programs and field experiments, these input parameters can now be moreaccurately derived. For example, the results from theFirst International Satellite Cloud Climatology Project(ISCCP) Field Experiment (FIRE) can provide important information for retrieving cloud parametersfrom satellite measurements and for specifying cloudoptical properties in radiative transfer calculations. Onthe other hand, fluxes at the top of the atmosphere(TOA) derived from

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Tristan S. L'Ecuyer and Graeme L. Stephens

provides a means for determining the vertical placement of the cloud in subsequent radiative transfer calculations. Furthermore, the optimal estimation framework provides error diagnostics for all retrieved parameters often lacking in other retrievals. Such estimates are critical for assessing uncertainties in the radiative fluxes that will be derived below. The dominant sources of uncertainty in the algorithm are due to a strong dependence on ice crystal habit, which is generally unknown, and

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Takmeng Wong, David F. Young, Martial Haeffelin, and Stephanie Weckmann

scientific approach used in the postlaunch validation of the ERBE-like CLW data. Section 3 presents a description of the postlaunch validation datasets, including both the clear-sky radiation and the meteorological data, and a brief overview of the radiative transfer model. The results for the ERBE-like CLW postlaunch validation and the initial ERBE-like CLW data application study on the 1998 ENSO event are given in sections 4 and 5 , respectively. Section 6 delivers the final summary and

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Wojciech W. Grabowski

only locally because the average surface heat flux is constrained by the prescribed radiative cooling. Consequently, interactive radiation is necessary to allow for the feedback between radiation and surface processes. However, once the interactive radiation is included, the role of clouds in the regulation of the SST should be considered because clouds do have a significant impact on the SST (e.g., Ramanathan and Collins 1991 ). It follows that effects of cloud microphysics on radiative transfer

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William C. Conant, V. Ramanathan, Francisco P. J. Valero, and Jens Meywerk

1. Introduction For the past five years, numerous studies ( Ohmura and Gilgon 1993 ; Wild et al. 1995 ; Ramanathan et al. 1995 ; Arking 1996 ) have identified a discrepancy on the order of 10–35 W m −2 between diurnally averaged net surface solar radiation measured at the earth’s surface and that predicted by radiative transfer models. By noting that the models agree with observations at the top of the atmosphere (TOA), Wild et al. attribute the deficit to an absorption by the atmosphere

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Dennis L. Hartmann, Leslie A. Moy, and Qiang Fu

average net radiation change near zero, when individual cloud types produce cloud radiative forcings of ±100 W m −2 ? In this study we take data from a region in the Tropics with persistent deep convective clouds that shows a strong cancellation between the longwave and shortwave effects of the cloud. We first show that we can approximate the ERBE observations of broadband radiative fluxes using ISCCP cloud data, observed atmospheric humidity and temperature profiles, and a radiative transfer model

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C. Poetzsch-Heffter, Q. Liu, E. Ruperecht, and C. Simmer

effects on the earth radiation budget. The ISCCP C1 cloud data fordaylight cases are used in combination with a radiative transfer model to estimate the outgoing broadbandradiative fluxes at the top of the atmosphere. Two tests are performed: the modeled narrowband filtered radiancesare verified against the ISCCP satellite observation data (internal tests) and the modeled broadband fluxes arecompared against ERBE data (external tests). After successful completion of the tests, the reflected solar (OSR

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Kazuhiko Masuda, H. G. Leighton, and Zhanqing Li

, in final form 27 December 1994)ABSTRACT An earlier parameterization that relates the outgoing solar flux at the top of the atmosphere to the fluxabsorbed at the surface is modified and extended to allow for variations in atmospheric properties that werenot considered in the original parameterization. Changes to the parameterization have also been introduced asa result of better treatment of water vapor absorption in the detailed radiative transfer calculations. Correctionsare introduced that

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Michael A. Kelly and David A. Randall

increase linearly from zero at the tropopause to a maximum at 600 mb, and to be independent of height between 600 mb and the TWI. This allows us to simplify the continuity equations for the CP region. A simple water vapor advection model diagnoses the precipitable water in the free troposphere. A radiative transfer parameterization, similar to that used for the WP region, gives the radiative cooling rate in the free troposphere. As described earlier, we have chosen to fix SSTs for this study. Because

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