Spatial and temporal variations of the inherent and apparent optical properties in a shallow coastal lake.
Spatial and temporal variations of the inherent and apparent optical properties in a shallow coastal lake.
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DOI：
10.1016/j.jphotobiol.2005.04.006
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发表时间：
2005-09
期刊：
影响因子：
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通讯作者：
Luca Bracchini;A. Dattilo;M. Falcucci;S. Loiselle;V. Hull;C. Arena;C. Rossi
中科院分区：
文献类型：
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作者：
Luca Bracchini;A. Dattilo;M. Falcucci;S. Loiselle;V. Hull;C. Arena;C. Rossi
在2002年的三个季节性调查中，在沿海泻湖的Fogliano的表观和固有的光学特性进行了测量。现场测量的紫外和可见光波段的辐照度数据允许估计相关的衰减系数。还对过滤（0.22 μ m）和未过滤的水样进行了实验室消光测量。现场测量和实验室测量相结合的办法使人们能够确定悬浮物和溶解物在水柱中紫外线和可见光辐射衰减和消失方面的作用。如上所述，悬浮物和溶解物对湖泊光学质量的影响受到颗粒物风再悬浮的影响：在低风速条件下，溶解物质在吸收紫外线和可见光辐射中的相对作用占主导地位（小于2.2 m s − 1），而在高风速下（3.9 m s-1），颗粒物再悬浮强烈影响衰减和消光测量。过滤和未过滤的水样和原位辐照度测量的分析波长的消光使我们能够定义新的光学参数和重要的湖沼和经典光学测量的相关性。通过以高空间分辨率（4平方公里内18个站点）进行采样，有可能证明光学和湖沼学特性的空间梯度，这些分布在所有三次调查中显示出一致的模式，并且对于用消光曲线光谱的光谱斜率估计的发色溶解有机物的特性非常重要。一个相对较高的光谱斜率被发现在南部盆地相对于北方，在那里的衰减系数和湖沼参数的最大值被发现。这些结果表明溶解有机质的不同来源和/或不同程度的光漂白。
Apparent and inherent optical properties in the coastal lagoon of Fogliano were measured in three seasonal surveys in 2002. Irradiance data from in situ measurements of ultraviolet and visible wavebands permitted to estimate the related attenuation coefficients. Laboratory extinction measurements on filtered (0.22 μm) and unfiltered water samples were also performed. The integrated approach between in situ and laboratory measurements allowed the determination of the role of the suspended and dissolved matter in the attenuation and extinction of ultraviolet and visible radiation within the water column. As noted, the impact of the suspended and dissolved matter on the lake optical quality was influenced by wind resuspension of particulate matter: the relative role of dissolved matter in the absorption of UV and visible radiation was prevailing at low wind velocity conditions (less than 2.2 m s−1), while at high wind velocities (3.9 m s−1), particulate matter resuspension strongly influenced the attenuation and the extinction measurements. The extinction in the analyzed wavelengths of filtered and unfiltered water samples and the in situ irradiance measurements allowed us to define new optical parameters and important correlations with limnological and classical optical measurements. By sampling at high spatial resolution (18 stations in 4 km2), it was possible to evidence a spatial gradient of the optical and limnological properties, these distributions showed a consistent pattern in all three surveys, and were important for the characterization of the chromophoric dissolved organic matter that was estimated with the spectral slope of the extinction curve spectra. A relatively higher spectral slope was found in the southern basin with respect to the northern, where the maximum values of the attenuation coefficients and limnological parameters were found. These results suggest different sources of dissolved organic matter and/or a different level of photobleaching.