Effective radiative properties of bounded cascade nonabsorbing clouds: Definition of the equivalent homogeneous cloud approximation
Effective radiative properties of bounded cascade nonabsorbing clouds: Definition of the equivalent homogeneous cloud approximation
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有界级联非吸收云的有效辐射特性：等效均匀云近似的定义
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
Andrey A. Ioltukhovski
中科院分区：
文献类型：
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作者：
ric Szczap;H. Isaka;M. Saute;Bernard Gulllerner;orologie Physique;France;Andrey A. Ioltukhovski
在本研究中，我们研究了非均匀非吸收云的辐射特性下的等效平面平行均匀云近似（EHCA），通过使用一维（1-D）有界级联非均匀云。有效光学厚度是根据EHCA定义的，要求非均匀云和其等效均匀云之间辐射收支的辐射通量分量相同。这种要求为定义非均匀非吸收云的有效光学厚度提供了合理的框架。我们分析了有效光学厚度对水平平均尺度和太阳入射角的依赖关系，并指定了非均匀云段可以被视为平行于平面的均匀云的条件。提出了一种有效光学厚度的参数化方法，它是平均光学厚度和相对云不均匀性参数的函数。最后，我们比较了EHCA和有效厚度近似，两者都基于有效光学深度的定义，并讨论了它们各自的有效光学深度之间的差异。
In the present study we investigated the radiative properties of inhomogeneous nonabsorbing clouds under the Equivalent plane-parallel Homogeneous Cloud Approximation (EHCA), by using the one-dimensional (1-D) bounded cascade inhomogeneous clouds. The effective optical depth was defined under the EHCA by requiring the identity of the radiant flux components of the radiation budget between the inhomogeneous clouds and their equivalent homogeneous counterparts. Such requirement provides a rational framework to define the effective optical depth of the inhomogeneous nonabsorbing clouds. We analyzed the dependency of the effective optical depth on the horizontal scale of averaging and solar incidence angle and specified the conditions under which an inhomogeneous cloud segment could be treated as a plane-parallel homogeneous cloud. A parameterization of the effective optical depth was proposed as a function of the mean optical depth and a relative cloud inhomogeneity parameter. Finally, we compared the EHCA with the effective thickness approximation, both based on the definition of the effective optical depth, and discussed the difference between their respective effective optical depths.