太湖水体浮游藻类吸收系数及影响因素分析

探讨研究了太湖水体浮游藻类的吸收系数的空间变化特征及其影响因素,2009年4月对太湖52个样点进行野外采样,并测量总叶绿素a浓度和浮游藻类的吸收系数。分析了色素包裹效应对比吸收系数的影响,通过计算得到太湖水体不同区域的色素包裹因子,并对浮游藻类的吸收系数进行包裹效应的校正;利用浮游藻类在440nm的吸收系数(aph(440))与675nm吸收系数(aph(675))的比值以及标准化比吸收系数谱来衡量太湖水体在不同区域、不同波段处,辅助色素对比吸收系数的影响。结果表明:(1)太湖水体在短波处浮游藻类的比吸收系数变化较大,而在675nm变化相对较小,梅梁湾水体的比吸收系数要低于其他区域的。(2)太湖水体比吸收系数的空间差异受包裹效应影响较为严重,包裹效应对比吸收系数空间变化的影响梅梁湾的水体要大于其他区域的,近岸水体要大于离岸较远的水体。(3)辅助色素对比吸收系数的影响相对较弱,主要集中在短波波段处,梅梁湾等水体辅助色素对浮游藻类的比吸收的影响要小于其他区域的,近岸水体要小于离岸较远的水体

Analysis of phytoplankton absorption coefficients and their effect factors in Taihu Lake

To estimate the spatial variation characteristics of Taihu Lake phytoplankton and its influencing factors, samples were taken at 52 sampling sites during Apr. 2009. Then the total concentration of Chla and absorption coefficient of phytoplankton were measured the very day the samples were delivered to the lab. In the present research, results on pigment package effect by former researchers were taken to calculate its influence on specific absorption coefficients, the power of package effect of different areas in Taihu Lake were estimated, and the package effort revision was done to absorption coefficient of phytoplankton. Ratio of blue and red band of absorption coefficients (a(ph) (440)/a(ph) (675)) and standardization specific absorption spectrum were used to measure the influence on specific absorption coefficients by accessory pigment in different areas of Taihu Laik and different bands. Results showed that (1) specific absorption coefficients of phytoplankton in Taihu Lake vary more in short wave bands than that at 675 nm, specific absorption coefficients in Meiliang Bay are lower than in other areas. (2) Spatial variation of specific absorption coefficients in Taihu Lake is seriously influenced by package effect, and this influence occurred more seriously in Meiliang Bay than in other areas and more seriously in alongshore water body than in offshore water body. (3) Influence on specific absorption coefficients by accessory pigment is relatively weak, and mostly concentrates in short wave band, while auxiliary pigment influence is less at 675 nm, and in Meiliang Bay accessory pigment influence is less than in other areas, and its influences are less in alongshore water body than in offshore water body.