Secchi disk depth: A new theory and mechanistic model for underwater visibility
Secchi disk depth: A new theory and mechanistic model for underwater visibility
复制标题
塞基盘深度：水下能见度的新理论和机制模型
DOI：
10.1016/j.rse.2015.08.002
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发表时间：
2015-11-01
影响因子：
13.5
通讯作者：
Lin, Gong
中科院分区：
文献类型：
--
作者：
Lee, ZhongPing;Shang, Shaoling;Lin, Gong
Secchi圆盘深度（ZsD）是一种水透明度的度量，其解释具有广泛的应用，从潜水员能见度到气候变化研究。在过去的60多年里，水下可见度理论解释了这种透明度，水下可见度理论是用于水中视觉测距的一般可见度理论的分支。然而，通过对水中视觉测距所涉及的物理过程的全面审查，我们表明，这一理论可能并不完全代表人眼看到的塞奇盘。此外，我们更新了对比度降低定律，可见性理论中的一个关键概念，并发展了一个新的理论模型来解释ZsD。与强烈依赖于光束衰减系数的经典模型不同，新模型仅依赖于对应于最大透明度的波长处的漫射衰减系数来进行这种解释。该模型随后验证使用一个大的（N = 338）数据集的独立测量，涵盖海洋，沿海和湖泊沃茨，结果显示出良好的协议（类似于18%的平均绝对差异，R-2 = 0.96）之间的测量和理论预测ZsD范围从30米，没有任何模型参数的区域调整。这项研究提供了一个更普遍的看法，视觉测距和机制模型，预计将显着提高目前的能力，通过卫星遥感监测全球水环境的透明度。(C)2015作者爱思唯尔公司出版
Secchi disk depth (ZsD) is a measure of water transparency, whose interpretation has wide applications from diver visibility to studies of climate change. This transparency has been explained in the past 60 + years with the underwater visibility theory, the branch of the general visibility theory for visual ranging in water. However, through a thorough review of the physical processes involved in visual ranging in water, we show that this theory may not exactly represent the sighting of a Secchi disk by a human eye. Further, we update the Law of Contrast Reduction, a key concept in visibility theory, and develop a new theoretical model to interpret ZsD. Unlike the classical model that relies strongly on the beam attenuation coefficient, the new model relies only on the diffuse attenuation coefficient at a wavelength corresponding to the maximum transparency for such interpretations. This model is subsequently validated using a large (N = 338) dataset of independent measurements covering oceanic, coastal, and lake waters, with results showing excellent agreement (similar to 18% average absolute difference, R-2 = 0.96) between measured and theoretically predicted ZsD ranging from 30 m without regional tuning of any model parameters. This study provides a more generalized view of visual ranging, and the mechanistic model is expected to significantly improve the current capacity in monitoring water transparency of the global aquatic environments via satellite remote sensing. (C) 2015 The Authors. Published by Elsevier Inc.