NSFGEO-NERC: Collaborative Research: Using Time-series Field Observations to Constrain an Ocean Iron Model

铁是海洋中浮游植物生长所必需的营养物质。因此，铁在调节海洋初级生产和碳循环中起着关键作用。因此，海洋生物学和化学模型必须考虑铁元素，以便探索过去、现在和未来海洋生产力的变化以及海洋在全球碳循环中的作用。在这个由美国国家科学基金会和英国自然环境研究委员会共同支持的联合项目中，来自百慕大大西洋时间序列研究（BATS）地区的实地数据将与一个已建立的、最先进的海洋生物地球化学模型相结合。通过利用BATS区域已知的季节尺度的物理、化学和生物变化、BATS核心数据提供的海洋学背景以及现有的区域物理环流模式，拟议的研究将产生普遍适用于开放海洋的过程相关信息。特别是，拟议的研究将侧重于了解海洋水体中溶解铁的大气输入、生物吸收、再生和清除去除，这些已成为海洋铁循环的主要不确定性。该项目将包括对K-12、本科生、研究生和博士后水平的重要教育和培训贡献，以及旨在解释研究及其重要性的公共宣传工作。海洋模型模拟铁的能力仍然很粗糙，因为对驱动溶解铁变化的机制了解不足，特别是对铁结合配体、胶体和颗粒在表层输入、上层海洋溶解铁的生物吸收、再生和清除中的作用了解不足。GEOTRACES项目产生的盆地尺度数据为测试和改进模型提供了重要资源，并进一步扩展了我们对海洋铁循环的机制理解。然而，这些数据只提供了准天气性的“快照”，这限制了它们在分离和识别控制上层海洋中溶解铁的过程中的效用。提出的研究旨在通过将来自BATS地区的时间序列数据与数值模拟实验相结合，提供对这些控制过程的机制见解。具体而言，将从五次巡航收集的水柱样本的化学分析中获得垂直（2000米以上）和横向（数十公里）分布的颗粒、溶解、胶体、可溶性和配体结合铁物种的季节性解析数据，跨越整个年度周期，与每月的BATS计划巡航共享。这些数据，连同来自BATS项目的辅助数据，将用于测试并为数值模拟实验提供信息，从而提高对控制海洋水柱中溶解铁的分布和动态的机制的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Iron is an essential nutrient for the growth of phytoplankton in the oceans. As such, iron plays key roles in regulating marine primary production and the cycling of carbon. It is thus important that models of ocean biology and chemistry consider iron, in order to explore past, present and future variations in marine productivity and the role of the ocean in the global carbon cycle. In this joint project involving researchers in the U.S. and the U.K., supported by both NSF and the Natural Environment Research Council (U.K.), field data from the Bermuda Atlantic Time-series Study (BATS) region will be combined with an established, state-of-the-art ocean biogeochemical model. By leveraging the known seasonal-scale physical, chemical and biological changes in the BATS region, the oceanographic context provided by the BATS core data, and an existing model of the regional physical circulation, the proposed study will yield process-related information that is of general applicability to the open ocean. In particular, the proposed research will focus on understanding the atmospheric input, biological uptake, regeneration and scavenging removal of dissolved iron in the oceanic water column, which have emerged as major uncertainties in the ocean iron cycle. The project will include significant educational and training contributions at the K-12, undergraduate, graduate and postdoctoral levels, as well as public outreach efforts that aim to explain the research and its importance.The ability of ocean models to simulate iron remains crude, owing to an insufficient understanding of the mechanisms that drive variability in dissolved iron, particularly the involvement of iron-binding ligands, colloids and particles in the surface input, biological uptake, regeneration and scavenging of dissolved iron in the upper ocean. Basin-scale data produced by the GEOTRACES program provide an important resource for testing and improving models and, by extension, our mechanistic understanding of the ocean iron cycle. However such data provide only quasi-synoptic 'snapshots', which limits their utility in isolating and identifying the processes that control dissolved iron in the upper ocean. The proposed research aims to provide mechanistic insight into these governing processes by combining time-series data from the BATS region with numerical modeling experiments. Specifically, seasonally resolved data on the vertical (upper 2,000 meters) and lateral (tens of kilometers) distributions of particulate, dissolved, colloidal, soluble and ligand-bound iron species will be obtained from the chemical analysis of water column samples collected during five cruises, spanning a full annual cycle, shared with the monthly BATS program cruises. These data, along with ancillary data from the BATS program, will be used to test and inform numerical modeling experiments, and thus derive an improved understanding of the mechanisms that control the distribution and dynamics of dissolved iron in the oceanic water column.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.