Collaborative Research: Autonomous Lagrangian Floats for Oxygen Minimum Zone Biogeochemistry

世界海洋的强氧最小区（OMZ）虽然只占海洋总体积的一小部分，但却承载着关键的海洋地球化学过程，是了解海洋氮循环及其海洋地球化学和同位素特征的核心。OMZ的是网站的一个大部分的海洋结合N损失为N2（25至50%），并通过共生15 N和18 O富集NO3 -占主导地位的海洋N同位素预算。主要悬而未决的问题包括这个N汇的大小，NO3 -损失和生物N2的生产之间的化学计量，微生物途径导致N2的生产，以及这些OMZ过程和有机物的表面出口以及物理循环之间的相互作用。PI的要求资金开发一个新的，在原位，自主的工具，研究在OMZ的N损失。它将允许在一定范围内的时间和空间尺度的变化，这是理解控制过程和更好地估计N-损失的幅度至关重要的观察。自主平台的持续部署对于检测OMZ对气候变化的任何反应至关重要。更广泛的影响： 氮通常是海洋中生物生产的限制性营养素，由于一些不确定性和问题，目前全球海洋氮平衡一直存在很多争议。一个成功的发展，这一建议的传感器浮动包可能有助于解决一些重要的问题上的空间和时间的可变性的OMZ。反过来，这种知识对于评估当前和未来海洋中的全球氮平衡至关重要。这个拟议的项目将涉及本科生，研究生和博士后的积极参与，以及K-12科学教师的培训。该项目还将促进与国际研究人员的合作。PI与新贝德福德海港的海洋探索中心合作，提供了一个教育推广部分，旨在帮助教师发展，并为马萨诸塞州南海岸的教师创建一个实地考察计划。该提案将支持博士后、研究生和本科生。

Intense oxygen minimum zones (OMZ) of the world's oceans, though constituting a small fraction of total oceanic volume, host critical biogeochemical processes and are central to understanding the ocean's N cycle and its biogeochemical and isotopic signatures. OMZ's are sites for a large portion of marine combined N loss to N2 (25 to 50%) and dominate the ocean N isotope budget through cogeneration of 15N and 18O enriched NO3 -. Major outstanding issues include the magnitude of this N sink, the stoichiometry between NO3 - loss and the production of biogenic N2, the microbial pathways leading to N2 production, as well as the interaction between these OMZ processes and the surface export of organic matter as well as physical circulation. The PI's request funding to develop a new, in situ, autonomous tool for studying N loss in OMZ's. It will allow observation of variability over a range in temporal and spatial scales that are critical for understanding controlling processes and better estimating the magnitude of N-loss. The sustained deployments possible with autonomous platforms will be critical for detecting any response of OMZ's to climate change.Broader Impacts: Nitrogen is often the limiting nutrient for biological production in the oceans, and the current global marine nitrogen balance has been in much debate due to a number of uncertainties and questions. A successful development of this proposed sensor-float package may help in resolving some of the important questions on the spatial and temporal variabilities of the OMZs. In turn, such knowledge is essential in assessing the global nitrogen balance in the current and future oceans. This proposed project would involve active participation of undergraduates, graduates and postdocs, as well as the training of a K-12 science teacher. This project would also foster collaboration with international researchers. The PI's have partnered with Ocean Explorium at New Bedford Seaport to provide an educational outreach component designed to aid teacher development and create a field trip program for teachers in the south coast of Massachusetts. The proposal will support post-doc, graduate and undergraduate students.