Evaluating Oceanic Nitrogen Fixation using Spatial Variations in the Natural Isotopic Composition of Nitrate in the Subsurface Waters of the Subtropical N. Atlantic

摘要OCE-9902450最近的研究表明，固氮可能在控制海洋结合氮的库存方面发挥核心作用，主要是深海中以溶解硝酸盐形式存在的氮。作为一种限制大部分海洋初级生产的常量营养素，氮不仅在维持海洋生态方面发挥着关键作用，而且在调节海洋吸收大气二氧化碳并将其固定为有机形式的能力方面也发挥着关键作用。在这项研究中，PIs将使用硝酸盐的同位素组成来评估和量化氮气固定在向北大西洋中部反热带地区供应结合氮方面的重要性。这种同位素方法将补充正在进行的直接测量海洋固氮率的努力。

ABSTRACT OCE-9902450Recent studies have suggested that nitrogen fixation may play a central role in controlling the oceanic inventory of combined nitrogen, primarily nitrogen in the form of dissolved nitrate in the deep ocean. As a macronutrient limiting primary production in much of the ocean, nitrogen not only plays a critical role in maintaining the ecology of the sea but also in regulating the capacity of the ocean to drawn down atmospheric carbon dioxide and fix it into organic form. In this study, the PIs will use the isotopic composition of nitrate to evaluate and quantify the importance of N2 fixation in supplying combined nitrogen to the oligotrohpic central North Atlantic. This isotopic approach will complement ongoing efforts to measure the rates of oceanic nitrogen fixation directly.