Iron in the Equatorial Undercurrent: Data and Models

美国JGOFS EqPac过程研究在赤道太平洋中部的一个主要新发现是，赤道暗流（EUC）中的铁是驱动生物新生产的最重要的铁来源，因此在该地区的碳循环。据推测，铁的来源是来自新几内亚附近的陆地来源。如果是这样的话，新几内亚的下游发生了什么？新几内亚的铁矿源可以向东追溯到多远？有一个严重缺乏的数据，需要从这个地区来测试这一来源的假设。在这个项目中，一个由美国和法国海洋科学家组成的国际小组，在华盛顿大学海洋地球化学家的领导下，将确定铁、锰、铝和钕在赤道太平洋沿着的带状剖面中的分布。 他们将寻求四个主要问题的答案：1。在赤道暗流中真的有一个铁的最大值吗？2.它的纬向梯度是多少？3.它的起源是什么？4.分布如何约束模型导出的通量？该团队将采用为期4年的综合实地、分析和建模方法。他们将沿沿着由东经143 '至西经140'进行一次纬向巡航，以测量溶解的、胶态的和总的酸溶性铁、锰和铝。将进行实验室研究，以测量溶解的和颗粒状的钕同位素以及颗粒状的铁、锰和铝。在巡航之前，将运行一个动力学-地球化学耦合模型，以预测铁的分布。他们也将模式的方法来估计相对重要性的物理与地球化学通量在中央（冷舌）和西方（暖池）赤道太平洋。科学的更广泛影响是，因为铁已被证明是限制该地区碳循环的元素，了解其来源将有助于更好地了解生物生产力和碳通量的过去和未来变化，并为预测对气候变化的反应。需要进行新的观测，以便将铁有效地纳入该地区的碳循环模型。该项目将与来自不同学科的几位外国科学家进行重大国际合作。这将包括来自新喀里多尼亚努梅阿（生物分析）、法国巴黎（建模）和法国图卢兹（钕分析）的科学家。它还将包括对研究生进行各种最先进的分析和建模技术以及跨学科海洋学方面的培训。

ABSTRACTOCE-0425721One of the principle new findings from the US JGOFS EqPac Process study in the central equatorial Pacific was that iron in the equatorial undercurrent (EUC) is the most important source of iron for driving biological new production and thus carbon cycling in this region. It has been hypothesized that the source of the iron is from terriginous sources in the vicinity of New Guinea. If that is the case, what is happening downstream from New Guinea? How far eastward can a New Guinea iron source be traced? There is a critical lack of data from this region that is needed to test this source hypothesis. This is a major lingering question that needs to be answered.In this project an international team of US and French ocean scientists, under the leadership of a marine geochemist at the University of Washington, will determine the distributions of iron, manganese, aluminum and neodymium in a zonal section along the equatorial Pacific. They will be seeking answers to four major questions: 1. Is there really a maximum of iron in the equatorial undercurrent? 2. What is its zonal gradient? 3. What is its origin? 4. How do the distributions constrain model derived fluxes? The team will use a 4-year integrated field, analytical and modeling approach. They will conduct a zonal cruise along the equator from 143'E to 140'W to measure dissolved, colloidal and total acid soluble Fe, Mn and Al. Laboratory studies will be carried out to measure dissolved and particulate neodymium isotopes and particulate Fe, Mn and Al. A coupled dynamical-biogeochemical model will be run to predict iron distributions before the cruise. They will also the model approach to estimate the relative importance of physical versus biogeochemical fluxes in the central (cold tongue) and western (warm pool) equatorial Pacific.The broader impacts of the science are that because iron has been shown to be an element limiting carbon cycling in this region, understanding its source will lead to greater understanding of past and future changes in biological productivity and carbon fluxes and provide a basis for predicting the response to climate change. New observations are required so that iron can be effectively incorporated into models of carbon cycling in this region. This project will feature major international collaboration with several foreign scientists from different disciplines. This will include scientists from Noumea, New Caledonia (biological analyses), Paris, France (modeling) and Toulouse, France (Nd analyses). It will also include training of graduate students in a wide range of state-of-the-art analytical and modeling techniques and interdisciplinary oceanography.