夏季太湖光学介质获取的光合有效辐射能量谱随深度变化规律的研究

根据2006-07-29～2006-08-01太湖41个站点测定的水体上、下行辐照度、非藻类颗粒物、浮游植物及有色溶解有机物(chromophoric dissolved organic matter, CDOM)的吸收系数，计算了单位水体中各介质所吸收光合有效辐射能量谱随深度的变化.结果表明，单位水体中的浮游植物获取光合有效辐射能量的标准化谱在表层有2个主峰，分别位于450 nm左右和675 nm左右，随着深度增加，位于450 nm左右的峰逐渐减弱，在藻型湖区和湖心区，衰减尤为明显，且该峰对应的波长出现红移现象；浮游植物获取的主要光能来源随深度的增加逐渐由400～500 nm和600～700 nm向600～700 nm过渡，在草型湖区的过渡速度相对缓慢，而在梅梁湾（藻型湖区）和湖心区却很快；单位水体中的非藻类颗粒物在表层获取的能量主要来自400～500 nm，但随深度的增加，其获取的能量主要来自500～600 nm;单位水体中CDOM获取光合有效辐射能量随深度的变化特征类似于非藻类颗粒物，但在草型湖区，其在500～600 nm获取能量的优势不如非藻类颗粒物明显.

Variation of Spectrum of Photosynthesis Available Radiation Absorbed by Underwater Optical Medium with Depth in Lake Taihu in Summer

Normalized spectrum of photosynthesis available radiation(PAR),which was absorbed by all kinds of medium per unit volume of water at different depths,was calculated by the data from downward and upward irradiance and absorption coefficients of phytoplankton,non-algae particles and chromophoric dissolved organic matter(CDOM) in 41 locations in Lake Taihu from July 29 to August 1,2006.The results showed that there were two peaks at about 450 nm and 675 nm in the normalized spectrum of PAR absorbed by phytopla...