Understanding submesoscale tracer transport

了解亚尺度示踪剂传输

• 批准号: 1924354
• 负责人: Joern Callies
• 金额: $ 54.89万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1924354&HistoricalAwards=false
• 关键词: Understanding; submesoscale; tracer; transport

This project is a theoretical and computational process-oriented investigation of submesoscale tracer transport in the ocean. The work plan consists of two research activities, the first addressing submesoscale vertical transport by mixed layer instabilities at the ocean surface, and the second investigating the effects of internal waves on lateral stirring in the ocean interior. Submesoscale oceanic flows have been implicated in supplying nutrients to the surface ocean, in providing stratification that traps phytoplankton in the sun-lit surface layer and helps them bloom, and in subducting particulate organic carbon from the mixed layer into the ocean interior. The work will advance fundamental understanding of these processes and is crucial for improved predictions of how Earth's climate will evolve in the coming decades and centuries. The results of this work directly benefit the scientific community developing climate models, which currently do not represent submesoscale processes. The project supports a postdoc, a graduate student, and two undergraduate students who will be trained in physical oceanography.The project will explore how submesoscale flows transport tracers such as potential temperature, salinity, carbon, nutrients, and oxygen. In the first part of the proposed work, the mechanisms by which submesoscale baroclinic mixed layer instabilities subduct water into the thermocline and fold thermocline water into the mixed layer will be investigated. In the second part, a mismatch between theoretical predictions for the spatial structure of passive tracers in the thermocline and observations of such tracer distributions in the real ocean will be addressed. The hypothesis that internal waves have a leading-order effect on the observed tracer distributions will be explored.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.

该项目是一项以理论和计算过程为导向的次中尺度示踪剂在海洋中传输的研究。工作计划包括两项研究活动，第一项研究海洋表面混合层不稳定对亚中尺度垂直输送的影响，第二项研究内波对海洋内部横向搅动的影响。次中尺度海洋流动涉及向表层海洋提供营养物质，提供层结将浮游植物困在阳光照亮的表层并帮助它们水华繁殖，以及将颗粒有机碳从混合层减少到海洋内部。这项工作将促进对这些过程的基本理解，对于改进对地球气候在未来几十年和几个世纪内如何演变的预测至关重要。这项工作的结果直接惠及开发气候模型的科学界，这些模型目前并不代表亚中尺度过程。该项目支持一名博士后、一名研究生和两名本科生，他们将接受物理海洋学方面的培训。该项目将探索亚中尺度气流如何传输示踪物，如潜在温度、盐度、碳、营养物质和氧气。在拟议工作的第一部分，将研究亚中尺度斜压混合层不稳定将水减少到温跃层中并将温跃层水折叠到混合层中的机制。在第二部分中，将讨论对温跃层中被动示踪剂空间结构的理论预测与在真实海洋中对这种示踪剂分布的观测之间的不匹配。将探索内波对观测到的示踪剂分布具有前序效应的假设。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。