摘要
根据Ｍｉｅ理论以及Ａｄｅｎ和Ｋｅｒｋｅｒ的理论，分别计算了纯水、纯冰和冰一水分层同心球在可见光和近红外波段的吸收、散射与衰减截面。结果表明，对于同样尺度大小的粒子，表面融化冰球或冰外壳包水球的单次散射特征值与纯冰纯水球的相比在整个太阳辐射短波段都相差不大，这是因为在此波段范围内冰和水的复折射指数的实部和虚部都很接近。此结果基本排除了０℃层附近表面融化冰晶粒子在太阳波段可能产生强吸收带，从而可以解释（部分的）云吸收异常规象这一想法。另一方面，在整层云吸收计算中，相对水含量可能较小但尺度较大的冰晶粒子的吸收是不应忽略的。
Based on the Mie theory and the theory by Aden and Kerker;; the absorption and scat-tering cross-sections of concentric spherical water and ice particles are computed in the solar radiationspectrum ranging from 0.3-to 4.0um of wavelength. The results show that because both the real andimaginary parts of refractive indices for water and ice are quite close in visible and near infrared bands;;there are little differences in the absorption and scattering properties between pure water;; pure icespheres and coneentric water-ice (ice-water) spheres. It is therefore unlikely to explain the phenomenonof cloud absorption anomaly simply by the surface melted ice particles which cause the bright bandsnear 0oC isotherm in stratiform clouds as seen in microwave radar observations. However;; ice particlesincluding water-ice crystals have to be taken into account in calculating the absorptivity of solar radia-tion by mixed-phase clouds since the absorption cross-section increases quickly with increasing particlesize and the effective radius of ice crystals are much larger than those of liquid water droplets.
出处
《大气科学》
CSCD
北大核心
1999年第2期233-238,共6页
Chinese Journal of Atmospheric Sciences
关键词
冰粒子
表面融化冰球
太阳辐射
吸收
短波段
ice particles surface melted ice spheres solar radiation cloud absorption
