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

最近的研究表明，固氮可能在控制海洋组合氮（主要是深海中溶解硝酸盐形式的氮）的库存中起核心作用。作为一种限制大部分海洋初级生产的大量营养物质，氮不仅在维持海洋生态方面起着关键作用，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起着关键作用。在本研究中，pi将使用硝酸盐的同位素组成来评估和量化N2固定在向低营养北大西洋中部提供组合氮方面的重要性。这种同位素方法将补充正在进行的直接测量海洋固氮速率的工作。

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.