An approximation to multiple scattering in the earth's atmosphere Almucantar radiance formulation
An approximation to multiple scattering in the earth's atmosphere Almucantar radiance formulation
复制标题
地球大气中多次散射的近似 Almucantar 辐射公式
DOI：
10.1175/1520-0469(1981)038
复制
发表时间：
1981
影响因子：
3.1
通讯作者：
A. Deepak
中科院分区：
文献类型：
--
作者：
M. Box;A. Deepak
摘要 过去，通过假设单散射近似，从太阳光环测量中反演气溶胶尺寸分布变得容易处理，因为通过求解完整的辐射传输方程而包含多重散射将使此类反演变得极其昂贵。最近，人们正在寻求一些方法来提高此类检索的准确性，而不增加单散射近似所提供的计算工作量。这导致了微扰近似的发展，它允许分子多重散射；气溶胶多重散射事件在很大程度上被忽略。在本文中，讨论了解释这种分子多重散射的经验表达式的推导，并通过太阳光环直接问题的一些例子说明了这种近似的准确性。
Abstract The retrieval of aerosol size distributions from solar aureole measurements, in the past, have been made tractable by assuming the single-scattering approximation, since the inclusion of multiple scattering by solving the complete radiative transfer equation would make such retrievals prohibitively expensive. Recently, ways have been sought to improve the accuracy of such retrievals without increasing the computational effort afforded by the single-scattering approximation. This has led to the development of a perturbation approximation, which makes allowance for molecular multiple scattering; aerosol multiple-scattering events are largely ignored. In this paper, the derivation of an empirical expression to account for this molecular multiple scattering is discussed, and the accuracy of this approximation is illustrated by some examples of the direct problem for the solar aureole.