Wei Jianwei, Lee Zhongping, Ondrusek Michael, Mannino Antonio, Tzortziou Maria, Armstrong Roy
Optical Oceanography Laboratory, School for the Environment, University of Massachusetts Boston, Boston, Massachusetts, USA.
NOAA/NESDIS Center for Weather and Climate Prediction, College Park, Maryland, USA.
J Geophys Res Oceans. 2016 Mar;121(3):1953-1969. doi: 10.1002/2015JC011415. Epub 2016 Mar 26.
The spectral slope of the absorption coefficient of colored dissolved and detrital material (CDM), (units: nm), is an important optical parameter for characterizing the absorption spectral shape of CDM. Although highly variable in natural waters, in most remote sensing algorithms, this slope is either kept as a constant or empirically modeled with multiband ocean color in the visible domain. In this study, we explore the potential of semianalytically retrieving with added ocean color information in the ultraviolet (UV) range between 360 and 400 nm. Unique features of hyperspectral remote sensing reflectance in the UV-visible wavelengths (360-500 nm) have been observed in various waters across a range of coastal and open ocean environments. Our data and analyses indicate that ocean color in the UV domain is particularly sensitive to the variation of the CDM spectral slope. Here, we used a synthesized data set to show that adding UV wavelengths to the ocean color measurements will improve the retrieval of from remote sensing reflectance considerably, while the spectral band settings of past and current satellite ocean color sensors cannot fully account for the spectral variation of remote sensing reflectance. Results of this effort support the concept to include UV wavelengths in the next generation of satellite ocean color sensors.
有色溶解和碎屑物质（CDM）吸收系数的光谱斜率（单位：纳米）是表征CDM吸收光谱形状的一个重要光学参数。尽管在天然水体中变化很大，但在大多数遥感算法中，该斜率要么保持为常数，要么在可见光域中用多波段海洋颜色进行经验建模。在本研究中，我们探索了利用360至400纳米紫外（UV）范围内新增的海洋颜色信息对半解析反演该斜率的潜力。在一系列沿海和开阔海洋环境中的各种水体中，已观察到紫外-可见波长（360 - 500纳米）的高光谱遥感反射率具有独特特征。我们的数据和分析表明，紫外域中的海洋颜色对CDM光谱斜率的变化特别敏感。在此，我们使用一个合成数据集表明，将紫外波长添加到海洋颜色测量中，将显著改善从遥感反射率中反演该斜率的效果，而过去和当前卫星海洋颜色传感器的光谱波段设置不能完全解释遥感反射率的光谱变化。这项工作的结果支持在下一代卫星海洋颜色传感器中纳入紫外波长的概念。
