Radiative Transfer Through Inhomogeneous Clouds: Stochastic Modeling Using Cloud Structure Observations

这项研究的目的是加深对云结构如何影响辐射特性的理解，并改进计算非均匀云中辐射传输的方法，用于参数化和遥感。这项研究将集中于使用随机辐射传输，其中集合平均辐射属性直接根据描述云不均匀的概率分布来计算。随机建模是合适的，因为有关云结构的信息本质上是统计的。来自飞机上的毫米波雷达和云探测器的数据将被用来描述液态水云的空间结构，包括云的可变性，以及随机转移概率分布。将进行辐射传输模拟，以了解云的不均匀性的哪些方面对平均辐射效果最重要，以及如何用几个简单的参数来最好地表达这些影响。模拟的辐射和通量将与飞机和地面辐射计进行比较。将寻求一种使用这些非均匀云参数来快速计算用于云辐射参数化的随机辐射传输的近似方法。还将进行确定性辐射传输模拟，以调查上升流辐射统计数据与用于云遥感的潜在不均匀性之间的关系。

Evans/Abstract The objective of this research is to increase the understanding of how cloud structure affects radiative properties and to improve methods of computing radiative transfer in inhomogeneous clouds for parameterizations an remote sensing. This research will focus on using stochastic radiative transfer, in which ensemble mean radiative properties are computed directly from probability distributions that describe cloud inhomogeneity. Stochastic modeling is appropriate because information about cloud structure is inherently statistical. Data from millimeterwave radars and cloud probes on aircraft will be used to characterize spatial structure in liquid water clouds, including within cloud variability, in terms of the stochastic transfer probability distributions. Radiative transfer modeling will be done to learn what aspects of cloud inhomogeneity are most important for the mean radiative effects and how these may be best expressed with a few simple parameters. The modeled radiances and fluxes will be compared with aircraft and ground based radiometers. An approximate method of using these inhomogeneous cloud parameters for rapidly computing stochastic radiative transfer for use in cloud radiation parameterizations will be sought. Deterministic radiative transfer modeling will also be done to investigate relationships between the statistics of upwelling radiances and the underlying inhomogeneity for use in remote sensing of clouds.