辽东湾海冰后向光场分布的研究

In situ studying of the backward radiance distribution within sea ice in Liaodong Bay

海冰光场分布特性的研究是冰区大气—海冰—海洋能量交换和生物特性研究的基础,通过设计"L"型辐亮度探头,运用自主研发的海冰高光谱辐射仪器于国内首次现场测量了辽东湾海冰内部光场的分布特性,研究发现海冰表层5 cm至底层在水平方向上光场各向同性,进而认为在所观测站点的附近,采集冰块测量光场分布不依赖于海冰侧表面的选择。采集海冰于现场建立的暗房内,研究发现相对辐亮度随着深度的增加呈渐近性分布减小,多重散射的影响随光程增加而增强,导致辐亮度对散射角的依赖逐渐减小,说明海冰是一种高散射特的物质。本文建立的海冰光场分布模型,可描述海冰内部任意深度和光传播方向的相对辐亮度,对海冰辐射传输研究具有一定的参考意义。

In order to research the mass budget during atmosphere-ice-ocean system and the biology in polar regions,it is necessary to research the solar radiance distribution within sea ice.In this study,a self-made hyperspectral radiation instrument of sea ice was used to observe the anisotropy and solar radiance distribution in sea ice for the first time.The results showed that the light distribution was isotropy in horizontal from the depth of 5 cm to ice bottom.Thereby,we can conclude that measurement of solar radiance distribution is independent of choosing ice side.A small dark room was built in situ with gobo.A large ice block was sampled and put into the dark room for observing the solar radiance distribution.The radiance profiles showed an asymptotic radiance distribution in sea ice.The effects of multiple scattering became strong with increasing pathlength,which caused the dependence of solar radiance on scattering angle（θ） became weak with depth.It showed that sea ice was a highly scattering medium.An optical model was brought forward to describe the solar radiance distribution at a random depth and θ.The results had some reference values to study the solar radiance distribution within sea ice.