Investigating the role and chemical nature of dissolved organic matter in marine environments

海洋溶解有机物（DOM）是世界海洋中一个神秘的碳基化合物库，其规模与大气中的二氧化碳库相当。它是由数千种独特的化合物组成的复杂混合物，其中只有约10%是真正可识别的。DOM的反应性变化很大，有些部分以小时到天的顺序变化，而另一些则以几千年的规模变化。DOM的化学性质驱动着反应性，为了理解DOM在从局部到全局的碳循环中扮演的不同角色，有必要了解DOM的化学性质。我们的研究计划的总体目标是了解DOM在全球碳循环中的作用以及它如何影响海洋生态系统。三个特定的目标将检查DOM化学的不同方面：******1。将反应性与详细化学分析联系起来***尽管分析技术最近取得了进展，但对于单个化合物的存在或不存在如何影响DOM的总体反应性，人们知之甚少。然而，正是这种反应性决定了DOM在海洋系统中的最终命运。我们将使用有条理的方法来连接DOM的结构和功能；重点是根据DOM在海洋环境中的反应性来确定其化学性质。将特别强调确定驱动DOM动态的重要功能组。******2。将光学测量与详细的化学分析相结合，将深入了解导致海水光学特性的原因，目标是为海洋过程开发更好的化学示踪剂。先进的分析技术将提供有关DOM的详细化学信息，而相对快速和低成本的光学技术将允许对DOM属性进行更好的空间和时间覆盖。发展这些联系将对海洋系统中DOM动力学的重要性提供更好的概括性分析。******3。海洋环境在全球碳循环中起着重要作用。就DOM而言，它们既受到海洋环境中碳循环的影响，也影响着海洋环境中碳循环的方式。了解快速变化环境中的DOM循环是了解气候变化对全球海洋影响的关键部分。北部和沿海地区正在迅速发生变化。我们的研究项目将集中在拉布拉多沿海和北大西洋等地区。我们将利用志愿观测船收集海洋环境中DOM的广泛时空数据集来研究DOM的动态。******这三个互补目标的结合以及它们将提供的结果将帮助我们了解海洋碳循环中一个具有挑战性但至关重要的部分。

Marine dissolved organic matter (DOM) is an enigmatic pool of carbon-based compounds in the world's oceans, representing a pool of carbon comparable in size to the atmospheric pool of carbon dioxide. It is a complex mixture of thousands of unique chemical compounds, of which only ~10% are truly identifiable. DOM reactivity varies considerably with some fractions turning over in the order of hours to days, and others turning over on the scale of millennia. The chemical nature of DOM drives reactivity and to understand the diverse roles that DOM plays in the carbon cycle from local to global scales, it is necessary to understand the chemistry of DOM. Our research program is defined by the overarching goal of understanding the role that DOM plays in the global carbon cycle and how it impacts marine ecosystems. Three specific objectives will examine different aspects of DOM chemistry: ******1. Linking Reactivity to Detailed Chemical Analysis***Despite recent advances in analytical techniques, little is known about how the presence or absence of individual compounds affects the overall reactivity of DOM. It is this reactivity, however, that determines the ultimate fate of DOM in the marine system. We will use methodical approaches to bridge the structure and function of DOM; focusing on defining the chemical nature of DOM in the context of its reactivity in the marine environment. Specific emphasis will be on determining the important functional groups that drive DOM dynamics.******2. Linking Advanced Analytical Techniques to Optical Properties***Combining optical measurements with detailed chemical analysis will give insight into what causes the optical properties of marine waters, with the goal of developing better chemical tracers for oceanic processes. Advanced analytical techniques will provide the detailed chemical information about DOM, and optical techniques, which are relatively rapid and low-cost, will allow for better spatial and temporal coverage of DOM properties. Developing these linkages will provide better synoptic analyses of the importance of DOM dynamics in marine systems.******3. Investigating the Dynamics of Organic Matter in Sensitive Marine Environments***Marine environments play important roles in the global carbon cycle. With respect to DOM, they are both affected by and affecting how carbon cycles in the marine environment. Understanding DOM cycling in rapidly changing environments is a crucial part of understanding the effects of climate change in the global ocean. Northern and coastal regions are changing rapidly. Our research program will focus on areas such as coastal Labrador and the North Atlantic Ocean. We will investigate DOM dynamics by taking advantage of Volunteer Observing Ships to collect broad spatial and temporal datasets of DOM in the marine environment.******The combination of these three complementary objectives and the results they will provide will help us to understand a challenging but crucial part of the marine carbon cycle.