...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Aquatic Sciences >Spectral Characterization Of Chromophoric Dissolved Organic Matter (cdom) In A Fjord (doubtful Sound, New Zealand)
【24h】

Spectral Characterization Of Chromophoric Dissolved Organic Matter (cdom) In A Fjord (doubtful Sound, New Zealand)

机译：峡湾中发色团溶解的有机物（cdom）的光谱表征（可疑声音，新西兰）

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Doubtful Sound, Fiordland National Park, New Zealand has a stable low salinity layer (LSL) at the surface due to the high annual rainfall and an additional freshwater input from the discharge of a hydroelectric power plant. Chromophoric dissolved organic matter (CDOM) distribution dynamics in this LSL were analyzed using Excitation Emission Matrix (EEM) fluorescence and UV/Vis absorption measurements. The levels of CDOM in surface water in Doubtful Sound were much higher than previously reported for coastal zones. CDOM analyzed by UV/ Vis absorbance and EEM fluorescence decreased by about 90 % within the first 5 m depth. In the first 5 m, the salinity gradient was extreme (5-34 salinity), creating a vertical mixing gradient, which appeared to be stable over time. The spectral slope S and the fluorescence index increased during vertical mixing within the first 5 m depth indicating changes in the CDOM chromophores. Observations during a strong rain event revealed that CDOM in a freshwater stream initially increased, but decreased with additional rain (same flow rate), which is an indication that most CDOM was quickly exported within these catchments. Furthermore, the lower CDOM input after substantial rain diluted the surface CDOM level and created a subsurface CDOM maximum. However, shortly after the rain event (< 24 h) the surface CDOM maximum with a steady decrease with depth was restored. The combination of extreme rainfall, pristine temperate rain forest and steep mountains with distinct watersheds creates a highly dynamic environment with very high terrestrial CDOM input. These CDOM dynamics and the high degree of scatter in the linear correlations between CDOM levels and salinity cannot be explained solely in terms of conservative mixing, but suggest that biophysical controls in the catchments and mixing with marine derived CDOM are involved in the dynamics of CDOM in this system.
机译：新西兰峡湾国家公园（Doordfulful Sound）的表面由于每年的高降雨量和水力发电厂的排放所产生的额外淡水输入，在地表具有稳定的低盐度层（LSL）。使用激发发射矩阵（EEM）荧光和UV / Vis吸收测量分析了该LSL中的发色溶解有机物（CDOM）分布动力学。令人怀疑之声中地表水中的CDOM含量比以前报道的沿海地区高得多。通过UV / Vis吸光度和EEM荧光分析的CDOM在前5 m深度内下降了约90％。在最初的5 m中，盐度梯度极高（5-34盐度），产生了垂直混合梯度，该梯度似乎随时间稳定。在前5 m深度内垂直混合期间，光谱斜率S和荧光指数增加，表明CDOM发色团发生了变化。在一次强降雨事件中的观察表明，淡水流中的CDOM最初有所增加，但随着雨水的增加（流速相同）而下降，这表明大多数CDOM迅速出口到这些流域。此外，大量降雨后较低的CDOM输入稀释了地表CDOM的水平，并造成了地下CDOM的最大值。但是，在降雨事件后（<24小时）不久，恢复了随深度而逐渐减小的表面CDOM最大值。极端的降雨，原始的温带雨林和陡峭的山脉与分水岭的结合创造了一个高度动态的环境，地面CDOM的输入量很高。这些CDOM动态和CDOM水平与盐度之间线性相关性的高度分散性不能仅通过保守混合来解释，而是表明流域中生物物理控制和与海洋衍生CDOM的混合涉及CDOM的动态。这个系统。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号