Understanding submesoscale tracer transport

本项目是海洋亚中尺度示踪剂输送的理论和计算研究。该工作计划包括两项研究活动，第一项研究由海洋表面混合层不稳定性引起的亚中尺度垂直输送，第二项研究内波对海洋内部横向搅拌的影响。亚中尺度的海洋流动涉及到向海洋表层提供营养物质，提供分层，使浮游植物困在阳光照射的表层并帮助它们繁殖，并将混合层中的颗粒有机碳俯冲到海洋内部。这项工作将促进对这些过程的基本理解，并对未来几十年和几个世纪地球气候将如何演变的改进预测至关重要。这项工作的结果直接有利于科学界开发气候模式，这些模式目前还不能代表亚中尺度过程。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流动如何运输示踪剂，如潜在温度、盐度、碳、营养物质和氧气。在本文的第一部分，将研究亚中尺度斜压混合层不稳定性将水俯冲到温跃层和将温跃层水折叠到混合层的机制。在第二部分中，将解决温跃层中被动示踪剂空间结构的理论预测与实际海洋中此类示踪剂分布的观测结果之间的不匹配问题。我们将探讨内波对观测到的示踪剂分布具有先导效应的假设。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。

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.