Representation of the Microphysical and Radiative Properties of Ice Clouds in SCMs and GCMs.

Mitchell, D. L. ; Arnott, W. P. ; Grubisic, V.

Technical Information Center Oak Ridge Tennessee

关键词: Ice;    Clouds;    Climate models;    Radiative properties;    Atmospheric circulation;   

RP-ID  :  DE2006842226

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

The goal of this project was (1) to characterize the ice particle size distribution as a function of temperature and ice water content (IWC) for mid-latitude and tropical anvil cirrus clouds; (2) to predict the ice mass sedimentation rates for these cirrus clouds; (3) to test and possibly improve upon a treatment of ice cloud radiative properties, developed during the previous ARM project. Once realized, these accomplishments would provide Global Climate Models (GCMs) with accurate parameterizations regarding ice cloud size distributions, ice sedimentation rates and radiative properties. This would be done in such a way that the treatments for ice particle size distributions (PSD), fall velocities and optical properties would use the same analytical formalism. For example, a gamma distribution was used for characterizing the PSD and predicting the sedimentation rates and radiative properties; the sedimentation and radiation schemes relate ice particle mass and projected area to ice particle maximum dimension using power-law expressions. This allows the cloud optical properties to be fully coupled with the cloud microphysics; something never achieved before.