Quantifying fluxes and characterizing compositional changes of dissolved organic matter in aquatic systems in situ using combined acoustic and optical measurements
Quantifying fluxes and characterizing compositional changes of dissolved organic matter in aquatic systems in situ using combined acoustic and optical measurements
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DOI：
10.4319/lom.2009.7.119
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发表时间：
2009-01-01
影响因子：
2.7
通讯作者：
Fujii, Roger
中科院分区：
文献类型：
--
作者：
Downing, Bryan D.;Boss, Emmanuel;Fujii, Roger
研究溶解有机物和颗粒有机物的动力学和地球化学行为是困难的，因为浓度和组成可能会响应非周期和周期性的物理和生物强迫而迅速变化。本文描述了一种用于定量通量和分析溶解有机质（DOM）动力学的方法。该方法使用光学和声学耦合测量，提供了研究过程和计算潮汐和其他水文环境中DOM通量所需的浓度和组成特征的可靠定量估计。每小时采集几次数据，持续2周或更长时间，采集频率和时间仅受功耗和数据存储容量的限制。我们利用旧金山湾河口自然潮汐湿地冬季部署的数据评估了该方法的能力和局限性。我们使用原位光学数据与传统实验室分析的离散水样的统计相关性来校准适合作为DOM浓度和表征代理的光学性质。结合流速测量，我们计算了DOC进入和流出潮汐湿地的长期剩余水平通量。数据集的子采样提供了最大采样间隔的估计，超过该采样间隔，通量估计的误差将显著增加。
Studying the dynamics and geochemical behavior of dissolved and particulate organic material is difficult because concentration and composition may rapidly change in response to aperiodic as well as periodic physical and biological forcing. Here we describe a method useful for quantifying fluxes and analyzing dissolved organic matter (DOM) dynamics. The method uses coupled optical and acoustic measurements that provide robust quantitative estimates of concentrations and constituent characteristics needed to investigate processes and calculate fluxes of DOM in tidal and other lotic environments. Data were collected several times per hour for 2 weeks or more, with the frequency and duration limited only by power consumption and data storage capacity. We assessed the capabilities and limitations of the method using data from a winter deployment in a natural tidal wetland of the San Francisco Bay estuary. We used statistical correlation of in situ optical data with traditional laboratory analyses of discrete water samples to calibrate optical properties suited as proxies for DOM concentrations and characterizations. Coupled with measurements of flow velocity, we calculated long-term residual horizontal fluxes of DOC into and out from a tidal wetland. Subsampling the dataset provides an estimate for the maximum sampling interval beyond which the error in flux estimate is significantly increased.