CAREER: Investigation of the Scattering and Radiative Properties of Ice and Mixed-Phase Clouds

该项目的目标是改进遥感应用中的冰云和混合相云的处理，以及气候和一般环流模式的云的参数化。这项研究由五大部分组成。其中的主要内容是对非球形冰粒的光散射进行基础研究，包括规则和不规则形状的晶体，这些晶体具有卷云的特征，以及由冰晶和过冷水滴的混合物组成的云。这项工作的核心是通过结合使用时域有限差分法(FTDT)、T矩阵方法和改进的几何光学方法(IGOM)来提高散射计算的精度和效率。其目的是为各种冰晶在太阳和红外波长下的吸收和散射特性建立一个数据库。其他研究部分包括：(1)将单个粒子的散射结果与卷云组成信息相结合，以确定用于卫星遥感的云的辐射性质；(2)将卷云和混合相云的整体辐射性质参数化，以应用于大规模大气模式；(3)开发从多光谱卫星测量推断云微观物理和光学性质的反演算法；(4)将光散射程序、辐射传输计划和反演算法整合为一个方便的计算软件包，供遥感和气候模型界使用。除了研究生和本科生的指导，该项目的教育部分包括开发一门整合辐射传输、云物理和大气遥感的课程，并最终建立辐射传输和遥感实验室，包括基于网络的教学材料。

The goal of this project is to improve the treatment of ice and mixed-phase clouds in remote sensing applications and in the parameterization of clouds for climate and general circulation models. The research consists of five broad components. Principal of these is a fundamental investigation of light scattering by nonspherical ice particles, including crystals of regular and irregular shapes characteristic of cirrus clouds and clouds composed of a mix of ice crystals and supercooled water droplets. This work centers on improving the accuracy and efficiency of scattering computations by using a combination of the finite-difference time domain (FTDT) method, T-matrix methods, and the improved geometric optics method (IGOM). The objective is to generate a data base for absorption and scattering properties of various ice crystal forms at solar and infrared wavelengths. The other research components include (1) integration of the scattering results for individual particles with information of the composition of cirrus clouds to determine the radiative properties of the clouds for the purposes of satellite remote sensing; (2) parameterization of the bulk radiative properties of cirrus and mixed-phase clouds for application to large-scale atmospheric models; (3) development of retrieval algorithms for inferring cloud microphysical and optical properties from multispectral satellite measurements; (4) integration of the light scattering programs, radiative transfer schemes, and retrieval algorithms in a convenient computational package for the remote sensing and climate modeling communities. Along with graduate and undergraduate student supervision, the educational component of the project comprises developing a curriculum that integrates radiative transfer, cloud physics, and atmospheric remote sensing, and ultimately establishing a Laboratory for Radiative Transfer and Remote Sensing, including web-based instructional material.