Collaborative Research: New Constraints on Marine Oxygen Cycling

海洋氧气与海洋环境中有机物的循环密切相关，因此，其预算对于解决海洋学中许多悬而未决的问题至关重要。在这项研究中，研究人员将测量三种氧同位素的数量，这些同位素可以联合收割机组成溶解在海洋沃茨中的分子氧气。当氧与其他物质发生反应时，这三种同位素的行为会因反应类型的不同而略有不同;这使得我们有可能确定导致海洋中不同地方存在氧的过程。这些结果有望产生新的见解，氧气如何与生物，有机物，矿物质和其他物质在各种海洋环境条件下相互作用，具有重要意义的海洋生产力和海洋中的低氧（低氧）区的未来研究。一名女研究生将获得这些新方法的实践经验，研究结果将通过社交媒体和视频向公众传播。在该项目中，研究人员将同时测量O2的五种稳定同位素变体，称为五重同位素分析，以提供对海洋氧循环的新限制。使用相结合的现场和实验研究，他们将评估五重同位素方法来跟踪海洋O2循环的潜力。利用这些新的分析方法，他们将在圣佩德罗海洋时间序列（SPOT）分析水柱中O2同位素的深度剖面和暗瓶孵育。这些测量，结合营养配置文件和补充实验室实验，将产生一个一阶的光合作用，呼吸和混合如何影响溶解海洋O2的同位素组成的理解。

Marine oxygen is strongly linked to the cycling of organic matter in the marine environment, and as such, its budget is central to addressing many of the outstanding questions in oceanography. In this study, researchers will measure the amounts of three isotopes of oxygen that can combine to make up the molecular oxygen gas dissolved in oceanic waters. When oxygen reacts with other substances, the three isotopes can behave in slightly different ways depending on the type of reactions; this makes it possible to identify the kinds of processes that have led to the existence of the oxygen found at different places in the ocean. These results are expected to yield new insights into how oxygen interacts with organisms, organic matter, minerals, and other substances under a variety marine environmental conditions, with important implications for future studies of ocean productivity and hypoxic (low oxygen) zones in the ocean. A female graduate student will gain hands-on experience with these new methods, and results from the research will be disseminated to the general public through social media and a video. In this project, researchers will make simultaneous measurements of five stable isotopic variants of O2, known as quintuple-isotopologue analysis, to provide new constraints on marine oxygen cycling. Using a combined field and experimental study they will evaluate the potential for the quintuple-isotopologue method to trace marine O2 cycling. Utilizing these novel analytical methods, they will analyze depth profiles and dark bottle incubations of O2 isotopologues in the water column at San Pedro Ocean Time Series (SPOT). These measurements, combined with nutrient profiles and complementary laboratory experiments, will yield a first-order understanding of how photosynthesis, respiration, and mixing affect the isotopologue composition of dissolved marine O2.