Determination of the Scaled Optical Thickness of Clouds from Reflected Solar Radiation Measurements
Determination of the Scaled Optical Thickness of Clouds from Reflected Solar Radiation Measurements
复制标题
根据反射太阳辐射测量确定云的缩放光学厚度
DOI：
--
复制
发表时间：
1987
期刊：
影响因子：
--
通讯作者：
M. King
中科院分区：
文献类型：
--
作者：
M. King
摘要 提出了一种根据反射太阳辐射测量来确定云的缩放光学厚度的方法。该过程将反射函数的测量结果与光学厚层的反射函数的渐近表达式进行比较。推导的解析公式明确显示了非吸收性大气的反射和透射函数对云光学厚度 (τc)、地面反照率 (Ag) 和不对称因子 (g) 的依赖性。对于非保守大气，反射函数对单散射反照率 (ω0) 和不对称因子的依赖性隐含在渐近函数和常数中。当缩放光学厚度 (1−g)τc≥??1.45（对应于光学厚度 τc≥??9 的云）时，这些保守和非保守大气的渐近表达式都被证明是有效的。通过利用光学厚、保守散射大气的反射函数的渐近表达式...
Abstract A method is presented for determining the scaled optical thickness of clouds from reflected solar radiation measurements. The procedure compares measurements of the reflection function with asymptotic expressions for the reflection function of optically thick layers. Analytic formulas are derived which explicitly show the dependence of the reflection and transmission functions of nonabsorbing atmospheres, on cloud optical thickness (τc), ground albedo (Ag) and asymmetry factor (g). For nonconservative atmospheres, the dependence of the reflection function on single scattering albedo (ω0) and asymmetry factor are contained implicitly in the asymptotic functions and constants. These asymptotic expressions for both conservative and nonconservative atmosphere are shown to be valid when the scaled optical thickness (1−g)τc≥??1.45, corresponding to clouds of optical thickness τc≥??9. By utilizing the asymptotic expression for the reflection function of an optically thick, conservatively scattering atmo...