Chromophoric dissolved organic matter (CDOM) in a subtropical estuary (Galveston Bay, USA) and the impact of Hurricane Harvey
Chromophoric dissolved organic matter (CDOM) in a subtropical estuary (Galveston Bay, USA) and the impact of Hurricane Harvey
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DOI：
10.1007/s11356-021-14509-x
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发表时间：
2021-05
影响因子：
5.8
通讯作者：
G. Gold-Bouchot;Samuel Polis;Lauren Elizabeth Castañon;Mayra Padilla Flores;A. Alsante;D. Thornton
中科院分区：
文献类型：
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作者：
G. Gold-Bouchot;Samuel Polis;Lauren Elizabeth Castañon;Mayra Padilla Flores;A. Alsante;D. Thornton
2017 年 8 月飓风哈维登陆，为研究极端淡水排放对亚热带河口（德克萨斯州加尔维斯顿湾）发色溶解有机物 (CDOM) 特性的影响提供了机会。荧光光谱（激发-发射矩阵）和三分量平行因子分析 (PARAFAC) 模型都确定了 CDOM 特性的变化。与 Coble 的峰值相比，分量 1 与峰值 C 相似，分量 2 与峰值 M 相似，分量 3 与峰值 B 相似。结果清楚地显示了具有不同 CDOM 特性的三个时期：旱季、雨季和飓风哈维。旱季的特点是光谱斜率、荧光和生物指数较高。雨季的特点是 PARAFAC 组分 1 和 2（类腐殖质）的值较高以及 350 nm 处的吸收系数。一些 CDOM 成分与盐度高度相关，表明混合保守。成分 3（类蛋白质）与盐度的相关性较低，表明海湾中发生了降解或生产过程。硅酸盐和NO3-+ NO2-与盐度呈负相关，与PARAFAC成分1和2呈正相关。PARAFAC成分3与溶解氧和叶绿素相关，表明CDOM荧光成分与浮游植物活性之间存在关系。飓风“哈维”过后立即观察到腐殖化指数较高，表明进入海湾的陆地有机物增加。飓风哈维增加了 CDOM 水平和腐殖化，而变化和变化似乎主要是由于圣哈辛托河而不是三一河的淡水排放造成的。淡水的流入足以消除加尔维斯顿湾的盐度梯度并显着改变 CDOM 特性。加尔维斯顿湾从飓风和相关淡水流量中迅速恢复，在不到 2 个月的时间内恢复到飓风前的 CDOM 特征。
The landfall of Hurricane Harvey in August 2017 provided the opportunity to study the impact of extreme freshwater discharge on chromophoric dissolved organic matter (CDOM) properties in a subtropical estuary (Galveston Bay, Texas). Both fluorescence spectroscopy (excitation-emission matrices) and a three-component parallel factor analysis (PARAFAC) model identified changes in CDOM properties. Comparing to Coble’s peaks, component 1 was similar to peak C, component 2 to peak M, and component 3 to peak B. Results clearly show three periods with distinct CDOM properties: a dry season, a wet season, and Hurricane Harvey. The dry season was characterized by higher values of the spectral slope and fluorescence and biological indices. The wet season was characterized by high values of PARAFAC components 1 and 2 (humic-like) and the absorption coefficient at 350 nm. Some CDOM components were highly correlated with salinity, indicating conservative mixing. Component 3 (protein-like) had a low correlation to salinity, suggesting degradation or production processes in the bay. Silicates and NO3-+ NO2-had negative relationships with salinity and a positive one with PARAFAC components 1 and 2. PARAFAC component 3 was correlated with dissolved oxygen and chlorophylla, suggesting a relationship between CDOM fluorescent components and phytoplankton activity. High values of the humification index were observed immediately after Hurricane Harvey, indicating increased input of terrestrial organic matter into the bay. Hurricane Harvey increased CDOM levels and humification, and the variability and changes seem to be mostly due to freshwater discharge from the San Jacinto River and not the Trinity River. The influx of freshwater was sufficient to eliminate the salinity gradient in Galveston Bay and significantly change CDOM properties. Galveston Bay recovered quickly from the hurricane and associated flux of freshwater, returning to pre-hurricane CDOM characteristics in less than 2 months.