Collaborative Research: Unraveling connectivity constraints and pathways of Sargassum and the nature of their variability by building on a Maxey-Riley framework for drift modeling

合作研究：通过建立用于漂移建模的 Maxey-Riley 框架，揭示马尾藻的连通性约束和路径及其变异性的本质

• 批准号: 2148500
• 负责人: Nathan Putman
• 金额: $ 19.78万
• 依托单位: LGL ECOLOGICAL RESEARCH ASSOCIATES, INC
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2148500&HistoricalAwards=false
• 关键词: Collaborative; Research; Unraveling; connectivity; constraints

Satellite imagery has revealed abundant pelagic Sargassum seaweed in the Sargasso Sea, the northwestern Gulf of Mexico and, in the last decade, a new recurrent zonal band, referred to as the Great Atlantic Sargassum Belt (GASB), often extending from the west coast of Africa to the Caribbean Sea. The magnitude of pelagic Sargassum in the tropical and subtropical Atlantic represents a new form of coastal hazard with direct impact on the water quality and living marine resources of the nearshore ecosystem. This project seeks to develop and implement a physical-biological transport model of Sargassum responding in a novel manner to the ocean and atmospheric circulations and changing environmental conditions. The model will account for the combined effects of ocean currents and wind drag mediated by Sargassum raft inertia, which will be a function of growth and mortality in response to ambient temperature and nutrient availability.This project would use first-principle-based Maxey–Riley framework of fluid mechanics for the study of inertial particle motion to develop a framework for modeling Sargassum drift. The investigators have extended and tested this application to investigating the drift of isolated objects floating at the ocean surface. This foundation, and further recent theoretical developments, will contribute to building a mechanistic physical–physiological model formulation for the movement of Sargassum rafts represented as networks of elastically interacting floating inertial particles whose configurations change according to a growth model. In the model, these changes in Sargassum raft size and shape will correspondingly affect their transport. The required carrying flow to conduct the proposed Sargassum connectivity investigation will be obtained from reanalysis systems and a multidata synthesis. The Sargassum transport model will be tested in the field by satellite tracking Sargassum rafts deployed in the Florida Current. Laboratory experiments in an air-water flume facility will be carried out to quantify buoyancy dependent leeway and constrain wave-induced drift effects. Tools for connectivity analysis and uncertainty quantification will be brought from ergodic nonlinear dynamics theory including set-oriented methods for framing asymptotically almost-invariant sets and the transition path theory for discrete Markov chains.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.

卫星图像显示，墨西哥湾西北部的马尾藻海中存在丰富的中上层马尾藻海藻，并且在过去十年中，出现了一条新的循环带，称为大大西洋马尾藻带 (GASB)，通常从美国西海岸延伸。非洲至加勒比海。热带和亚热带大西洋中上层马尾藻的规模代表了一种新形式的沿海灾害，对近岸生态系统的水质和海洋生物资源产生直接影响。旨在开发和实施一种以新颖的方式响应海洋和大气环流以及不断变化的环境条件的马尾藻物理生物运输模型，该模型将解释由马尾藻筏惯性介导的洋流和风阻力的综合影响。将是生长和死亡率对环境温度和养分可用性的函数。该项目将使用基于第一原理的 Maxey-Riley 流体力学框架来研究惯性粒子运动，以开发一个用于模拟马尾藻的框架研究人员已经扩展并测试了该应用程序，以研究漂浮在海洋表面的孤立物体的漂移。这一基础以及最近的理论发展将有助于建立代表马尾藻筏运动的机械物理生理模型。作为弹性相互作用的漂浮惯性粒子的网络，其配置根据生长模型而变化，在模型中，马尾藻筏尺寸和形状的这些变化将相应地影响它们的运输，将从中获得进行所提出的马尾藻连通性调查所需的载流。再分析系统马尾藻传输模型将通过部署在佛罗里达海流中的卫星跟踪马尾藻筏进行现场测试，并将在空气-水水槽设施中进行实验室实验，以量化浮力相关的余地并限制波浪引起的漂移。用于连通性分析和不确定性量化的工具将来自遍历非线性动力学理论，包括用于构建渐近几乎不变集的面向集合的方法和离散马尔可夫链的转移路径理论。通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。

项目成果

Improving satellite monitoring of coastal inundations of pelagic Sargassum algae with wind and citizen science data

利用风和公民科学数据改善对远洋马尾藻沿海淹没的卫星监测

• DOI: 10.1016/j.aquabot.2023.103672
• 发表时间: 2023
• 期刊: Aquatic Botany
• 影响因子: 1.8
• 作者: Putman, Nathan F.;Beyea, R. Taylor;Iporac, Lowell Andrew;Triñanes, Joaquin;Ackerman, Emilie G.;Olascoaga, Maria J.;Appendini, Christian M.;Arriaga, Jaime;Collado-Vides, Ligia;Lumpkin, Rick
• 通讯作者: Lumpkin, Rick

Sinking Sargassum

沉没的马尾藻

• DOI: 10.1029/2022gl100189
• 发表时间: 2022
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Putman, Nathan F.;Hu, Chuanmin
• 通讯作者: Hu, Chuanmin