Wang Yuan-Dong, Liu Dian-Wei, Song Kai-Shan, Zhang Bai, Wang Zong-Ming, Jiang Guang-Ji, Tang Xu-Guang, Lei Xiao-Chun, Wu Yan-Qing
Northeast Institute of Geography and Agricultural Ecology, Chines Academy of Sciences, Changchun 130012, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2011 Jan;31(1):162-7.
Spectral characteristics and the magnitudes of light absorption by suspended particulate matter were determined by spectrophotometry in this optically complex Lake Chagan waters for the purpose of surveying the natural variability of the absorption coefficients to parameterize the bio-optical models for converting satellite or in-situ water reflectance signatures into water quality information. Experiments were carried out on seasonal frozen Lake Chagan, one representative inland case-2 water body in Northeast of China. Particulate absorption properties analyzed using the field data on July 15th and October 12th 2009 were measured using the quantitative filter technique to produce absorption spectra containing several fractions that could be attributed to two main optical active constituents (OACs) phytoplankton pigments and non-algal particulates (mineral sediments, and organic detritus). Results suggested that the suspended particulate matter (SPM) concentration was higher while phytoplankton biomass (chlorophyll-a concentration) was lower in July and that in October. The spectral shape of total suspended particulate matter resembled that of non-algal particulates which contributed greater than phytoplankton in total particulate absorption during both periods. An obvious absorption peak occurring at around 440 nm exhibited an increase in phytoplankton contribution in October. Non-algal particulate absorption at 440 nm (a(NAP) (440)) had better correlation with total suspended particulate matter concentration than that with chlorophyll-a over the two periods. Light absorption by phytoplankton pigments in the Chagan lake region was generally lower than that of non-algal components. Chl. a dominating phytoplankton pigment composition functioned exponentially with its absorption coefficients at 440 and 675 nm specifically, the average values of which in July were 0.146 8 m2 x mg(-1) and 0.050 3 respectively while in October they were 0.153 3 and 0.013 2 m2 x mg(-1) varying regionally and seasonally due to the changes in specific composition, light and nutrient conditions.
为了测量吸收系数的自然变异性，以便将卫星或现场水体反射特征转换为水质信息来参数化生物光学模型，通过分光光度法测定了查干湖这种光学复杂水体中悬浮颗粒物的光谱特性和光吸收量。实验在季节性封冻的查干湖进行，它是中国东北一个典型的内陆二类水体。利用2009年7月15日和10月12日的现场数据，采用定量过滤技术测量分析了颗粒物吸收特性，以生成包含几个组分的吸收光谱，这些组分可归因于两种主要光学活性成分（OACs）——浮游植物色素和非藻类颗粒物（矿物沉积物和有机碎屑）。结果表明，7月悬浮颗粒物（SPM）浓度较高，而浮游植物生物量（叶绿素a浓度）较低，10月则相反。总悬浮颗粒物的光谱形状类似于非藻类颗粒物，在这两个时期，非藻类颗粒物对总颗粒物吸收的贡献大于浮游植物。10月在440nm左右出现一个明显的吸收峰，表明浮游植物的贡献增加。在这两个时期，440nm处非藻类颗粒物吸收（a(NAP)(440)）与总悬浮颗粒物浓度的相关性优于与叶绿素a的相关性。查干湖地区浮游植物色素的光吸收通常低于非藻类成分。叶绿素a是浮游植物色素组成的主要成分，其在440nm和675nm处的吸收系数呈指数函数关系，7月其平均值分别为0.1468m2·mg-1和0.0503，10月分别为0.1533和0.0132m2·mg-1，由于特定组成、光照和营养条件的变化，其值存在区域和季节差异。
