Collaborative Research: Particle scavenging controls on trace element distributions

合作研究：微量元素分布的粒子清除控制

• 批准号: 2124014
• 负责人: Jefferson Moore
• 金额: $ 73.57万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2124014&HistoricalAwards=false
• 关键词: Collaborative; Research; Particle; scavenging; controls

Nearly all of the photosynthesis in the oceans is carried out by microscopic, single-cell “plants” called phytoplankton. The photosynthesis by phytoplankton forms the base of the food chain, supporting almost all life in the oceans. One of the key nutrients that phytoplankton need to grow is iron, which is often in short supply in ocean surface waters and can limit the phytoplankton growth and photosynthesis rates. This project seeks to better understand the cycling of iron in the oceans, focusing on the removal of iron from the oceans by particle scavenging. Particle scavenging refers to dissolved iron sticking to large, sinking particles, which ultimately remove iron to the sediments. This modeling study will simulate iron cycling in the oceans, along with the cycling of several different metal isotopes, that are also subject to removal by particles scavenging, but do not act as nutrients for phytoplankton. This will help separate the biological influences on iron distributions, from the impacts of particle scavenging and other physical processes. The external sources of iron to the oceans coming from dust deposition, ocean sediments, river runoff, and the seafloor hydrothermal vents will also be evaluated. This work is important for understanding how climate change and human activities will modify the iron cycle and impact biogeochemistry in the future. This project will also support two graduate students and an undergraduate student researcher. The model simulations will be evaluated and constrained with extensive comparisons to field measurements of iron and the other key variables. The GEOTRACES program has recently produced a global set of ship measurement surveys, with full depth measures of numerous isotopes and trace elements, including iron, that are ideal for evaluating the prognostic ocean model (Community Earth System Model (CESM) ocean component). The GEOTRACES datasets are also ideal for incorporation into our offline, inverse model (OCIM, CYCLOCIM) which can interpret the still sparse observations in the context of 3D circulation and biogeochemistry. The simulations of 230Th, 232Th, 231Pa, and Fe cycling will improve mechanistic understanding of particle scavenging and place stronger observational constraints on the patterns and magnitude of external lithogenic sources of trace elements to the oceans. Results and products from this study, with the ocean model component of the Community Earth System Model (CESM), will be incorporated into future versions of CESM, to improve the current ability to predict how ocean biogeochemistry and marine ecosystems will respond to climate change along a range of potential future climate trajectories.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.

海洋中几乎所有的光合作用都是通过微观的单细胞“植物”（称为浮游植物）进行的。浮游植物的光合作用构成了食物链的基础，几乎支持海洋中的所有生命。浮游植物需要生长的关键营养之一是铁，这通常是在海面水域中供应的，并且可以限制浮游植物的生长和光合作用速率。该项目旨在更好地了解海洋中铁的循环，重点是通过粒子清除从海洋中去除铁。粒子清除是指溶解的铁粘在大的下沉颗粒上，最终将铁去除到沉积物中。这项建模研究将模拟海洋中的铁循环，以及几种不同金属同位素的循环，这些循环也可能会被颗粒清除的去除，但不能充当浮游植物的营养素。这将有助于将生物学对铁分布的影响与粒子清除和​​其他物理过程的影响分开。还将评估来自灰尘沉积，海洋沉积物，河流径流和海底水热通风孔的海洋外部来源。这项工作对于理解气候变化和人类活动将如何改变铁循环并影响生物地球化学的生物地球化学很重要。该项目还将支持两名研究生和一名本科生研究人员。将通过与铁和其他关键变量的现场测量进行广泛的比较，对模型模拟进行评估和约束。 Geotraces计划最近进行了一组全球的船舶测量调查，对包括铁的众多同位素和痕量元素进行了完整的深度测量，这些元素是评估预后海洋模型（社区地球系统模型（CESM）海洋组件）的理想选择。 GeoTraces数据集也是我们离线，逆模型（OCIM，CycloCim）保险的理想选择，该模型可以解释3D圆圈和生物地球化学背景下仍然稀疏的观察结果。第230、232、231PA和Fe循环的模拟将提高对粒子清除的机械理解，并将更强的观察限制放在痕量元素的外部岩性源的模式和大小上。这项研究的结果和产品以及社区地球系统模型（CESM）的海洋模型组成部分将纳入CESM的未来版本中，以提高当前的海洋生物地球化学和海洋生态系统的能力，并将海洋生态系统响应于气候变化，将沿着一系列潜在的气候轨迹对气候变化做出反应。该奖项反映了NSF的范围范围的范围，这反映了NSF的范围，依靠NSF的构建范围，是范围的范围。审查标准。