Showing papers by "Kuo-Nan Liou published in 2001"
TL;DR: In this paper, a 3D radiative transfer model was developed to simulate the transfer of solar and thermal infrared radiation in inhomogeneous cirrus clouds, employing Cartesian coordinates.
Abstract: A three-dimensional (3D) radiative transfer model has been developed to simulate the transfer of solar and thermal infrared radiation in inhomogeneous cirrus clouds. The model utilizes a diffusion approximation approach (four-term expansion in the intensity) for application to inhomogeneous media, employing Cartesian coordinates. The extinction coefficient, single-scattering albedo, and asymmetry factor are functions of spatial position and wavelength and are parameterized in terms of the ice water content and mean effective ice crystal size. The correlated k-distribution method is employed for incorporation of gaseous absorption in multiple-scattering atmospheres. Delta-function adjustment is used to account for the strong forward-diffraction nature in the phase function of ice particles to enhance computational accuracy. Comparisons of the model results with those from plane-parallel (PP) and other 3D models show reasonable agreement for both broadband and monochromatic results. Three-dimension...
32 citations
TL;DR: The measured scattering properties of ice crystals generated in a cold chamber also compare reasonably well with the theoretical results based on calculations from a unified theory of light scattering by ice crystals that use the particle size distribution measured in the chamber.
Abstract: We report on a small, lightweight polar nephelometer for the measurement of the light-scattering properties of cloud particles, specifically designed for use on a balloonborne platform in cirrus cloud conditions. The instrument consists of 33 fiber-optic light guides positioned in a two-dimensional plane from 5° to 175° that direct the scattered light to photodiode detectors–amplifier units. The system uses an onboard computer and data acquisition card to collect and store the measured signals. The instrument’s calibration is tested by measurement of light scattered into a two-dimensional plane from small water droplets generated by an ultrasonic humidifier. Excellent comparisons between the measured water-droplet scattering properties and expectations generated by Mie calculation are shown. The measured scattering properties of ice crystals generated in a cold chamber also compare reasonably well with the theoretical results based on calculations from a unified theory of light scattering by ice crystals that use the particle size distribution measured in the chamber.
27 citations