"Collaborative Research: Constraining the marine nitrogen cycle using a new approach to measuring nitrogen isotopes of chlorins"

考虑到海洋氮循环控制碳循环的假设作用，氮生物地球化学的重建对于提高我们对全球地球化学循环的理解至关重要。哈佛大学和罗德岛大学的科学家们提议完成一种新的分析方法的开发，以实现对沉积卟啉氮同位素组成（del15N）值的可靠、高通量分析。卟啉- del15n的值应反映氮循环的整体状态，特别是海洋表层养分供需状况。此外，科学家们计划测量原核生物和真核生物、末次冰期至全新世沉积物中氮同位素的分异，并分析地中海沉积物和白垩纪海洋缺氧事件。这项研究的目的是帮助限制反硝化和固氮的全球重要性。至于更广泛的影响，这项研究的结果将提高我们对水柱生物地球化学的理解，这将是预测氮循环对气候事件的反应的关键。哈佛大学的一名研究生和罗德岛大学的一名本科生将得到支持和培训。

Given the hypothesized role for the marine nitrogen cycle in governing carbon cycling, reconstructions of nitrogen biogeochemistry are critical to improve our understanding of global geochemical cycles. Scientists from Harvard University and the University of Rhode Island propose to complete their development of a new analytical method to achieve reliable, high-throughput analyses of nitrogen isotope composition (del15N) values of sedimentary porphyrins. Values of porphyrin-del15N should reflect both the overall state of the nitrogen cycle, and in particular, conditions of nutrient supply and demand in the surface ocean. In addition, the scientists plan to measure the nitrogen isotopic fractionation in prokaryotes and eukaryotes, Last Glacial Maximum-to-Holocene sediments from sites characterized by different nitrogen dynamics, and analyze Mediterranean sapropels and Cretaceous Ocean Anoxic Events. The goal of this research is to help constrain the global importance of denitrification and nitrogen fixation.As regards broader impacts, results from this research will improve our understanding of water column biogeochemistry which will be critical in predicting the response of the nitrogen cycle to climatic events. One graduate student at Harvard University and one undergraduate student from the University of Rhode Island will be supported and trained.