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Andrew K. Heidinger, Christopher O’Dell, Ralf Bennartz, and Thomas Greenwald

1. Introduction Difficulties in the accurate and rapid simulation of radiation that is multiply scattered have limited the use of satellite infrared and microwave observations in cloudy regions for data assimilation in numerical weather prediction (NWP) schemes. This paper presents a technique that allows for computationally efficient modeling of azimuthally symmetric radiative transfer in moderately scattering atmospheres. Azimuthally symmetric radiation refers to radiation that has no

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Jarred L. Burley, Steven T. Fiorino, Brannon J. Elmore, and Jaclyn E. Schmidt

typical deterministic or “standard” atmospheric type data utilized by many modern radiative transfer models. Thus, AFIT/CDE has produced an atmospheric effects definition and reference, the Laser Environmental Effects Definition and Reference (LEEDR; Fiorino et al. 2008b ), that allows the export of the first-principles atmospheric characterizations. LEEDR contains both an internally consistent line-by-line and correlated- k distribution radiative transfer algorithm capable of assessing path

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Alan J. Geer, Peter Bauer, and Christopher W. O’Dell

1. Introduction The small-scale variability of cloud and precipitation must be carefully modeled in order to get accurate simulations of atmospheric radiative transfer. For example, the amount of overlap between different cloud layers can strongly affect quantities such as heating rates and the earth’s albedo (e.g., Morcrette and Fouquart 1986 ; Morcrette and Jakob 2000 ). At microwave frequencies, the nonlinear dependence of radiance on hydrometeor amount causes a “beamfilling effect” in

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Sebastian W. Hoch, C. David Whiteman, and Bernhard Mayer

heating. Recent developments in radiative transfer modeling now allow simulations of the radiative field in complex terrain to be readily made. Photon-tracing models such as the Monte Carlo code for the physically correct tracing of photons in cloudy atmospheres (MYSTIC) now allow for a realistic representation of complex surface terrain ( Mayer 2009 ; Mayer et al. 2010 ). The role of radiative cooling within topography has previously been investigated for real basins ( Kondo et al. 1989 ) and

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Ming Liu, Young-Joon Kim, and Qingyun Zhao

radiative processes highly depends on the accuracy of radiative transfer (RT) parameterizations, by which solar and thermal infrared (IR) radiative fluxes are generated and radiative heating rates are calculated for atmospheric temperature tendency integration and the surface energy budget. Radiation modeling is critically important in both general circulation models and regional models. Thus, the incorporation of an accurate and efficient RT parameterization into NWP models has become a crucial step to

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Chenxi Wang, Ping Yang, Steven Platnick, Andrew K. Heidinger, Bryan A. Baum, Thomas Greenwald, Zhibo Zhang, and Robert E. Holz

-based optical thickness retrievals are limited to lower values of optical thickness in comparison with solar reflectance–based techniques and require accurate surface temperature and atmospheric state profiles (e.g., Huang et al. 2004 ; Cooper and Garrett 2010 ). Some studies demonstrated that shortwave and IR observations provide complementary information and therefore the combination of the two can provide more consistent retrievals ( Baran and Francis 2004 ). To simulate the radiative transfer (RT) in

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Ulrike Wissmeier, Robert Buras, and Bernhard Mayer

inexpensive one-dimensional radiative transfer solvers. The need of a good radiative transfer scheme that considers three-dimensional effects becomes more and more important when going to higher model resolutions, however. Then, the net radiation flux between neighboring model columns can no longer be neglected. A widely employed method for calculating irradiances in NWP or LES models is the so-called independent column approximation (ICA), also called independent pixel approximation (IPA)—in the

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Chen Zhou, Ping Yang, Andrew E. Dessler, Yongxiang Hu, and Bryan A. Baum

semiwidth and length of a hexagonal ice crystal. The size distribution of HOIC is the same as that in ROIC, except that only plates with a size greater than 100 μ m are considered to be quasi-horizontally oriented since smaller plates can have large tilt angles ( Klett 1995 ). Subsequently, the phase matrix is normalized before being used in the Monte Carlo radiative transfer simulations. Fig . 2. Illustration of the scattering coordinates and scattering angles. The forward amplitude matrix is used to

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Christopher W. O’Dell, Andrew K. Heidinger, Thomas Greenwald, Peter Bauer, and Ralf Bennartz

1. Introduction There is currently a need for fast yet accurate radiative transfer (RT) models for scattering atmospheres. Numerical weather prediction (NWP) models rely increasingly on assimilation of radiance data directly, rather than on derived products ( English et al. 2000 ). Operational centers are beginning to contemplate assimilating microwave and infrared radiances under all-weather conditions, instead of under clear skies only, as is currently done ( Greenwald et al. 2002 ). For this

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Thomas P. Ackerman, Kuo-Nan Liou, and Conway B. Leovy

JOURNAL OF APPLIED METEOROLOGY VOLUM~I$Infrared Radiative Transfer in Polluted Atmospheres~ Tao~s P. Ac~Emo. sD~p~r~n2nl oJ A~mosptv~ri~ Sd~a~s, U~si~:~ oJ W~ing~n, ~z~ 9819~K~O-N~ L~o~ Dep~n~ of M~ology, Un~ly of U~h, 5~ La~ City 84112 CO~ B. L~Departm~ of Atmosp~ S~es, Un~s~y of W~hingt~, Se~ 9~195(M~usc~pt received 17 M~rch 1975, ~ re~d fo~ 8 Sep~mber 1975)ABSTRACT A four-stream, multi-layered radiative

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