Bio-optical properties in waters influenced by the Mississippi River during low flow conditions
Bio-optical properties in waters influenced by the Mississippi River during low flow conditions
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DOI：
10.1016/s0034-4257(02)00163-3
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发表时间：
2003-04-10
影响因子：
13.5
通讯作者：
Miller, RL
中科院分区：
文献类型：
--
作者：
D'Sa, EJ;Miller, RL
2000 年 4 月和 10 月的航行期间，对墨西哥湾北部湾的生物光学特性的时空模式进行了研究，这一年密西西比河的流量异常低。在研究区域观察到高度可变的表面叶绿素 a 浓度（0.1 至 17 mg m(-3)）和有色溶解有机物（CDOM）吸收（412 nm 处为 0.07 至 1.1 m(-1)），这些浓度通常随着海水盐度的增加而降低，近岸最高，近海站降低。吸收、散射和漫反射衰减系数的光学特性反映了这些分布，其中浮游植物颗粒和 CDOM 影响了大部分空间、垂直和季节变化。漫衰减系数 K-d(lambda) 和光谱遥感反射率 R-rs(lambda) 是吸收和后向散射系数 a(lambda) 和 b(b)(lambda) 的线性函数，通过向下平均余弦 mu(d) 和 SeaWiFS 波段的变量 f/Q 之比，对于生物光学条件变化很大的水域。尽管各种 R-rs(lambda) 比率组合显示出与 412 nm 处的表面 Chl a 浓度和 CDOM 吸收高度相关，但使用 R-rs(490)/R-rs(555) 和 R-rs(510)/R-rs(555) 比率导出的幂律方程提供了从 SeaWiFS 反射数据中对 Chl α 浓度和 CDOM 吸收的最佳反演。 (C) 2002 Elsevier Science Inc. 保留所有权利。
Spatial and temporal patterns of bio-optical properties were studied in the Northern Gulf of Mexico during cruises in April and October of 2000, a year during which the discharge volume from the Mississippi River was unusually low. Highly variable surface Chl a concentrations (0.1 to 17 mg m(-3)) and colored dissolved organic matter (CDOM) absorption (0.07 to 1.1 m(-1) at 412 nm) were observed in the study region that generally decreased with increasing salinity waters, being highest nearshore and decreasing at offshore stations. The optical properties of absorption, scattering, and diffuse attenuation coefficients reflected these distributions with phytoplankton particles and CDOM contributing to most of the spatial, vertical, and seasonal variability. The diffuse attenuation coefficient K-d(lambda) and spectral remote sensing reflectance R-rs(lambda) were linear functions of absorption and backscattering coefficients a(lambda) and b(b)(lambda) through the downward average cosine mu(d) and the ratio of variables f/Q at the SeaWiFS wavebands for waters with widely varying bio-optical conditions. Although various R-rs(lambda) ratio combinations showed high correlation with surface Chl a concentrations and CDOM absorption at 412 nm, power law equations derived using the R-rs(490)/R-rs(555) and R-rs(510)/R-rs(555) ratios provided the best retrievals of Chl alpha concentrations and CDOM absorption from SeaWiFS reflectance data. (C) 2002 Elsevier Science Inc. All rights reserved.