Colored dissolved organic matter(CDOM)is a major component of dissolved organic matter (DOM) in seawater. Due to intensely absorbing UV and blue light and influencing the color of seawater, it is key factor to nature ecosystem, water color remote sensing and carbon cycle investigation. A CDOM determining system was designed and fabricated. The system mainly consists of light source, fiber, liquid core waveguide (LCW) flow cell and micro spectrometer. We took the surface water samples from 16 sites near coast of Jiulongjiang estuary where the salinity ranging from 0 to 30. We used our instrument to analyze the samples simultaneously on ship to obtain their absorption spectra, calculate the CDOM absorption coefficients and the slope of the log-linearized absorption spectra, and compared the data with the values using a cary 100 spectrometer. The dynamic range of a(355nm) ,as the abundance of CDOM, for our LCW measurement was 0. 52 - 2. 47m-1,while for cary 100 it was 0. 47 - 2. 45m-1. Correlation between in situ measured CDOM and the laboratory measurement was high, R2 = 0. 996. These results support the conclusion that the system is suitable for determining CDOM absorption spectrum on ship.%有色溶解有机物(CDOM)是海水中溶解有机物的主要成分之一,由于它强烈吸收紫外光和蓝光,对海洋的水色产生影响,是研究自然生态系统、水色遥感、水体碳循环的重要因素.实验设计并搭建了基于液芯波导(LCW)的CDOM测量系统.系统主要由光源、光纤、液芯波导流通池、蠕动泵和微型光谱仪构成.对九龙江河口近岸盐度0～30梯度范围内16个站位的表层水样进行采样,并用本系统进行现场分析,获得各个站位水样的吸收光谱,计算CDOM吸收系数a和指数拟合后的光谱斜率S与Cary 100Bio分光光度计的测定结果比较.本系统测定355 nm处的吸收系数a(355nm)作为CDOM的丰度指数,其范围为0.52～2.47m-1,Cary100Bio测定a(355nm)的范围为0.47～2.45m-1.现场与实验室测量所得吸收系数基本一致(R2=0.996),说明本系统适用于海上船载分析测量CDOM的吸收光谱.
展开▼
