Optical closure in marine waters from in situ inherent optical property measurements.
Optical closure in marine waters from in situ inherent optical property measurements.
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DOI：
10.1364/oe.24.014036
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发表时间：
2016-06
期刊：
影响因子：
3.8
通讯作者：
Ina Lefering;Fethi Bengil;C. Trees;R. Röttgers;D. Bowers;A. Nimmo-Smith;J. Schwarz;D. McKee
中科院分区：
文献类型：
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作者：
Ina Lefering;Fethi Bengil;C. Trees;R. Röttgers;D. Bowers;A. Nimmo-Smith;J. Schwarz;D. McKee
利用辐射传输模拟的光学闭合可用于确定固有光学特性（IOPs）和辐射测量的原位测量的一致性。对一系列沿海和海洋水域的现场吸收和衰减剖面数据应用了三种散射校正，但发现对这些台站随后的关闭尝试只有非常有限的影响。对数变换测量和模拟的最拟合回归曲线的中位斜率在0.92 - 1.24之间，显示出Ed和Lu随深度的低估趋势。这只能部分解释为模拟中没有包含CDOM和叶绿素的荧光发射。有几个站点的多个体散射函数相关数据处理步骤表现不佳，这表明在散射光子角分布的建模中可能存在未解决的特征。因此，一般的光学闭合仍然存在问题，即使在许多情况下，在数据集中，测量和模拟的辐射数据之间的匹配在25%的RMS%E以内。这些结果对于依赖于光学闭包的应用具有重要意义，例如将海洋颜色数据同化到耦合的物理生态系统模型中。
Optical closure using radiative transfer simulations can be used to determine the consistency of in situ measurements of inherent optical properties (IOPs) and radiometry. Three scattering corrections are applied to in situ absorption and attenuation profile data for a range of coastal and oceanic waters, but are found to have only very limited impact on subsequent closure attempts for these stations. Best-fit regressions on log-transformed measured and modelled downwards irradiance, Ed, and upwards radiance, Lu, profiles have median slopes between 0.92 - 1.24, revealing a tendency to underestimate Ed and Lu with depth. This is only partly explained by non-inclusion of fluorescence emission from CDOM and chlorophyll in the simulations. There are several stations where multiple volume scattering function related data processing steps perform poorly which suggests the potential existence of unresolved features in the modelling of the angular distribution of scattered photons. General optical closure therefore remains problematic, even though there are many cases in the data set where the match between measured and modelled radiometric data is within 25% RMS%E. These results are significant for applications that rely on optical closure e.g. assimilating ocean colour data into coupled physical-ecosystem models.