COLLABORATIVE RESEARCH: IMPACT OF DOM SOURCE AND PHOTOOXIDATION ON CARBON CYCLING IN ESTUARIES

在不了解河流和河口溶解有机质(DOM)的类型、大小和时间尺度的情况下，向海洋输送的溶解有机物及其化学和同位素特征将受到区域和全球的限制。为此，弗吉尼亚海洋科学研究所和老道明大学的科学家计划采用一种多技术方法来确定控制总溶解有机物(TDOM)在约克河和特拉华河河口系统中停留期间的结构变化和最终氧化损失的光化学和微生物过程。这两个温带河口具有不同的总溶解有机质时代和来源。利用光化学(即辐照)、稳定和放射性同位素、结构工具(即13C-核磁共振)和细菌降解实验，初级营养资料调查将评估光化学和微生物过程如何机械地影响TDOM出口的定性和定量性质，以及河口DOM的光化学反应活性如何因河流来源的年龄、组成和光氧化/光漂白而改变。

ABSTRACTOCE-0327423OCE-0327446Without understanding the type, magnitude and time scale over with dissolved organic matter (DOM) gets modified in rivers and estuaries, the regional and global delivery of total dissolved organic matter delivered to the ocean and its chemical and isotopic signatures will be poorly constrained. For this reason, scientists from the Virginia Institute of Marine Science and Old Dominion University plan to carry out a multi-technique approach to determine the photochemical and microbial processes that control the structural alteration and terminal oxidative losses of total dissolved organic matter (TDOM) during its residence in the York and Delaware River estuarine systems. These two temperate estuaries are characterized by different total dissolved organic matter ages and sources. Utilizing photochemical (i.e., irradiation), stable and radio-isotopic, structural tools (i.e., 13C-NMR) and bacterial degradation experiments, the PIs will evaluate how the photochemical and microbial processes mechanistically impact the qualitative and quantitative nature of TDOM export and how photochemical reactivity of estuarine DOM is changed by riverine source age, composition and photo-oxidation/photobleaching.