黄、东海区光谱漫衰减系数特性研究

Characteristics of Diffuse Attenuation Coefficient in the Yellow Sea and East China Sea Areas

利用剖面仪于 2003 年 3—4 月在黄、东海实测的水下向下辐照度剖面数据,建立了黄、东海光谱漫衰减系数模型。在 400 ～ 600 nm 波段,漫衰减系数和波长之间存在近似的线性关系。每一个波段的漫 2衰减系数与 490 nm 波段的漫衰减系数 Kd(490) 最小二乘法线性回归的 R 值都超过了 0.99。通过对光谱 2散射直线的斜率与波长进行回归,可以得到光谱散射曲线的斜率与波长的关系,R 值为 0.974。利用本文建立的光谱漫衰减系数模型,可以从一个已知波段漫衰减系数反演出任何另外一个波段的漫衰减系数,从而大大地减少了在水色反演中未知因子的个数。并且,利用现场的实测数据对模型进行了检验和误差分析。各通道的反演误差随着 Kd (490) 的增加而总体降低,在 Kd (490) 较低区域,反演误差值虽然较高,但大部分集中在 20 % 以内。各通道平均反演误差范围在 9% 以下。

An approximate linear relationship is given between the diffuse attenuation coefficient and the wavelength of light in the 400～600 nm. From this relationship , we can estimate the diffuse attenuation coefficient to be an unknown wavelength from the diffuse attenuation coefficient in a single measured wavelength. This approximation is based on the measurements in the cases I and II water collected with SPMR at 83 stations in the Yellow Sea and the East China Sea. The R2 value of least-squares linear regressions curves between each band's diffuse attenuation coefficient and that in the wavelength of 490 nm is over 0.99. The R2 value of that between the slope of curves and the wavelength is 0.974. A separate data set from these 83 stations is used to validate the relationship. Although the error between the modeled and measured diffuse attenuation coefficients is higher in clear water than ocean side water, the average error of that is 6.0 % for the entire test data set over the wavelength of 400～600 nm. Using the model, you can reduce the unknown factor.