黄海水体生物发光所致离水辐亮度变化及其与固有光学性质和深度的联系

Variation of Water Leaving Radiance Originated From Bioluminescence in the Yellow Sea and Its Relationship With Inherent Optical Properties and Depth

利用黄海不同季节实测生物发光数据,结合同步测量的固有光学性质数据,基于辐射传输模拟,分析了生物发光所致离水辐亮度(L_(w-bio))的数值变化和光谱变化,并讨论其与固有光学性质及生物发光所处深度的联系。主要结论如下:(1)黄海水体L_(w-bio)幅值不仅具有显著的季节变化特征,同时具有显著的空间变化特征,影响其变化的主要因素除水体本身发光生物的丰度和发光能力外,与水体自身固有光学性质和发光生物所处深度有关。(2)在光谱变化方面,L_(w-bio)最大峰值波长漂移不仅随着生物发光所处深度加深而增大,同时与固有光学性质有关,在固有光学性质其值较大的水体,当生物发光的光源深度位于表层以下,L_(w-bio)峰值波长可由蓝光波段(474 nm)变为绿光波段(最大可移动至578 nm);在固有光学性质其值较小的清澈水体中,辐亮度光谱变化较弱,其L_(w-bio)峰值波长仍在蓝光波段范围内(最大可移动至500 nm)。(3)黄海海域宽泛的固有光学性质对生物发光光源的几何深度反演影响较大,但可通过L_(w-bio)的光谱信息,反演光源的几何深度。

Based on the radiative transfer simulation model,using the measured bioluminescence intensity data from different seasons in the Yellow Sea,combined with the simultaneous measured inherent optical properties data,this study analyzes the numerical and spectral variation of the water leaving radiance originating from bioluminescence(L_(w-bio))and discusses its relationship with the inherent optical properties and the depth of bioluminescence.The main research results of this paper are as follows:(1)L_(w-bio)in the Yellow Sea has significant seasonal and spatial variation characteristics.Besides the bioluminescence abundance and ability of the water column,the L_(w-bio)is also related to the inherent optical properties of the water column and the depth of the bioluminescence source.(2)In terms of spectral variation,the maximum wavelength shift of L_(w-bio)increases with the deepening of the depth of bioluminescence source and related to the inherent optical properties.In the water column with a large value of inherent optical properties,when the depth of the bioluminescence source is below the surface water column,the maximum wavelength of L_(w-bio)can change from blue band(474 nm)to green band(up to 578 nm);In the water column with a low value of inherent optical properties,the variation of radiance spectrum is weak.Even if the depth of the bioluminescence source increases,the maximum wavelength of L_(w-bio)is still in the blue band(up to 500 nm).(3)Although the broad inherent optical properties of the Yellow Sea have a great impact on the geometric depth retrieval of the bioluminescence source,the geometric depth of the bioluminescence source can be retrieved from the spectral information of L_(w-bio).