Mechanisms Responsible for Mesoscale Eddy Energy Dissipation (MeRMEED)

负责中尺度涡流能量耗散的机制 (MeRMEED)

• 批准号: NE/N001745/3
• 负责人: Eleanor Frajka-Williams
• 金额: $ 17.19万
• 依托单位: NATIONAL OCEANOGRAPHY CENTRE
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FN001745%2F3
• 关键词: Mechanisms; Responsible; Mesoscale; Eddy; Energy

Over the last decades, oceanographers have been searching for the missing mixing in the ocean to complete the ocean energy budget. Answering questions of where energy is added to the oceans, and where it is removed, helps us to understand the drivers of ocean circulation. With the advent of high-resolution satellite measurements of surface currents in the 1990s, scientists could see that the oceans were filled with swirling vortices of water called mesoscale eddies. While eddies are present in all ocean basins, with currents inside the eddies sometimes exceeding 1 m/s, they disappear from satellite measurements preferentially at western boundaries. There are several possibilities for why eddies disappear at western boundaries: they may radiate energy away, contribute energy to large scale ocean circulation, or lose energy locally through turbulence and dissipation. Of these candidate terms, previous work has suggested that local dissipation is strong enough to explain a substantial part of the eddy disappearance. Our aim is to determine how and why eddies are losing energy at the western boundaries. These results and our measurements will then be made available to scientists involved in numerical simulations of the ocean. As a longer-term goal, the results of our research may help guide how eddies are represented in ocean models, which is one of the critical areas needing improvement in climate simulations. However, due to the fledgling nature of the science in this field, that eventual goal is still several steps away.Fundamental physics dictate that most eddies move slowly westward, and these eddies are visible in satellite measurements of sea surface height a few months before they arrive at the boundary. In the project MeRMEED, we will watch the eddies in near real-time satellite data, and when an appropriate eddy approaches the east coast of North America, we will deploy a small team of researchers, with advanced instruments, to meet the eddy upon arrival. There, we will survey the eddy using high-resolution profilers deployed from small boats and autonomous underwater vehicles called Seagliders. After the ship-based survey is completed, the gliders will continue to observe the eddies for several months, as the eddies are slowly disappearing. These gliders transmit their measurements via satellite communications back to our base station in England. We also plan to use the existing observations from the joint UK/US-funded RAPID programme, measuring ocean circulation at 26N. We will install additional high-resolution velocity and temperature meters on one of these moorings, to make continuous observations of the eddies over 18 months. From the survey, glider and moored measurements, we will be able to assess how important local dissipation is to the disappearance of eddies. We will use our findings to shed light on the processes responsible for eddy disappearance from the oceans, and how those processes change in time.

在过去的几十年里，海洋学家一直在寻找海洋中缺失的混合，以完成海洋能源预算。回答能量在哪里被添加到海洋中以及在哪里被移除的问题，有助于我们了解海洋环流的驱动因素。随着 20 世纪 90 年代高分辨率卫星测量地表水流的出现，科学家们可以看到海洋中充满了被称为中尺度涡流的水涡流。虽然所有海洋盆地都存在涡流，且涡流内部的水流有时超过 1 m/s，但卫星测量结果显示涡流主要在西部边界消失。涡流在西部边界消失的原因有多种可能：它们可能会辐射能量，为大规模海洋环流贡献能量，或者通过湍流和耗散局部损失能量。在这些候选术语中，先前的工作表明局部耗散足以解释涡流消失的很大一部分。我们的目标是确定涡流如何以及为何在西部边界失去能量。这些结果和我们的测量结果将提供给参与海洋数值模拟的科学家。作为一个长期目标，我们的研究结果可能有助于指导海洋模型中涡流的表示方式，这是气候模拟中需要改进的关键领域之一。然而，由于该领域的科学刚刚起步，距离最终目标还有几步之遥。基础物理学表明，大多数涡流缓慢向西移动，并且这些涡流在形成前几个月在海面高度的卫星测量中可见。到达边界。在MeRMEED项目中，我们将通过近乎实时的卫星数据观察涡流，当适当的涡流接近北美东海岸时，我们将部署一个小型研究团队，配备先进的仪器，在到达时与涡流会合。在那里，我们将使用小船和名为 Seagliders 的自主水下航行器部署的高分辨率剖面仪来调查涡流。船基测量完成后，滑翔机将继续观察涡流数月，因为涡流正在慢慢消失。这些滑翔机通过卫星通信将测量结果传输回我们位于英格兰的基站。我们还计划使用英国/美国联合资助的 RAPID 计划的现有观测结果，测量北纬 26 度的海洋环流。我们将在其中一个系泊处安装额外的高分辨率速度和温度计，以便在 18 个月内对涡流进行连续观测。通过调查、滑翔机和系泊测量，我们将能够评估局部耗散对于涡流消失的重要性。我们将利用我们的发现来揭示海洋涡旋消失的过程，以及这些过程如何随时间变化。

项目成果

Structure and Variability of the Antilles Current at 26.5°N

26.5°N安的列斯海流的结构和变化

• DOI: 10.1029/2018jc014836
• 发表时间: 2019
• 期刊: Journal of Geophysical Research: Oceans
• 作者: Meinen, Christopher S.;Johns, William E.;Moat, Ben I.;Smith, Ryan H.;Johns, Elizabeth M.;Rayner, Darren;Frajka‐Williams, Eleanor;Garcia, Rigoberto F.;Garzoli, Silvia L.
• 通讯作者: Garzoli, Silvia L.

Corrigendum

勘误表

• DOI: 10.1080/17415977.2016.1264148
• 发表时间: 2016
• 期刊: Inverse Problems in Science and Engineering
• 影响因子: 1.3
• 作者: Crabb M

Ocean Mixing

海洋混合

• DOI: 10.1016/b978-0-12-821512-8.00021-9
• 发表时间: 2022
• 作者: Frajka-Williams E

Encyclopedia of Ocean Sciences

海洋科学百科全书

• DOI: 10.1016/b978-0-12-409548-9.10852-8
• 发表时间: 2019
• 作者: Frajka-Williams E

OceanGliders: A Component of the Integrated GOOS

• DOI: 10.3389/fmars.2019.00422
• 发表时间: 2019-10
• 期刊: Frontiers in Marine Science
• 影响因子: 3.7
• 作者: P. Testor;B. de Young;D. Rudnick;S. Glenn;D. Hayes;Craig M. Lee;C. Pattiaratchi;K. Hill;E. Heslo