Dynamics of the Orkney Passage Outflow (DynOPO)

奥克尼群岛航道流出动力学 (DynOPO)

• 批准号: NE/K012843/1
• 负责人: Michael Meredith
• 金额: $ 63.29万
• 依托单位: British Antarctic Survey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FK012843%2F1
• 关键词: Dynamics; Orkney; Passage; Outflow; DynOPO

During the last three decades, the Antarctic Botttom Water (AABW) filling the bulk of the global ocean abyss has exhibited a striking warming and contraction in volume over much of the world ocean, particularly in the Atlantic basin. While the causes of these changes are unknown, available evidence suggests that, in the Atlantic Ocean, the warming and contraction of AABW may be caused by changes in winds over the northern Weddell Sea, where much AABW is produced. This hypothesis asserts that those winds regulate the volume and temperature of the AABW exported northward via the Orkney Passage (a major AABW exit route from the Weddell Sea) by altering the intensity of the turbulent mixing between AABW and overlying warmer waters in the passage.In this proposal, we set out to test and, if necessary, redefine this hypothesis by:(1) carrying out the first systematic measurements of how AABW flows through the Orkney Passage, how its properties change along the way, and what processes are important in determining the AABW flow and transformation in the passage;(2) determining how and why the flux and properties of AABW in the Orkney Passage respond to wind forcing on time scales of up to several years.To address task (1) above, we will measure the velocity and properties of AABW and the intensity of turbulent mixing at several key locations in the passage. The observations will be obtained both with instruments lowered to the seabed from a ship and with a novel autonomous underwater vehicle, which is particularly effective at measuring a range of potentially crucial processes occurring near the ocean floor. To address task (2), we will enhance an array of moorings recently deployed in the Orkney Passage by the British Antarctic Survey to monitor the flux and properties of AABW. We will equip the moorings with sufficient oceanographic instrumentation to identify the processes determining the AABW's response to wind forcing, which are not resolved by the present array.We will use our findings from tasks (1) and (2) to define how and why the volume and properties of the AABW escaping the Weddell Sea through the Orkney Passage react to changes in winds. Armed with this new understanding, we will revisit the widespread AABW warming and contraction observed over recent decades, and inform the international strategy to monitor future changes in AABW circulation.

在过去的三十年里，南极底层水（AABW）填充了全球海洋深渊的大部分，在世界大部分海洋，特别是大西洋盆地，表现出显着的变暖和体积收缩。虽然这些变化的原因尚不清楚，但现有的证据表明，在大西洋，AABW的变暖和收缩可能是由北方威德尔海上空的风的变化引起的，那里产生了大量的AABW。这一假说认为，这些风调节了通过奥克尼海峡向北输出的AABW的体积和温度（威德尔海的主要AABW出口路线）通过改变AABW和通道中上覆的温暖沃茨之间的湍流混合强度。在本提案中，我们着手测试并在必要时重新定义这一假设：（1）对AABW如何流经奥克尼海峡进行首次系统测量，其性质如何沿沿着变化，以及哪些过程是决定通道中AABW流动和转化的重要因素;（2）确定奥克尼海峡AABW的通量和性质如何以及为什么在长达几年的时间尺度上响应于风强迫。我们将测量AABW的速度和特性以及通道中几个关键位置处的湍流混合强度。观测将通过从船上下放到海底的仪器和一种新型自主水下航行器进行，这种水下航行器在测量海底附近发生的一系列潜在关键过程方面特别有效。为了解决任务（2），我们将加强英国南极调查局最近在奥克尼海峡部署的系泊装置阵列，以监测AABW的通量和特性。我们将为系泊设备配备足够的海洋学仪器，以确定确定AABW对风强迫的响应的过程，这是目前阵列无法解决的问题。我们将使用任务（1）和（2）中的发现来定义通过奥克尼通道逃离威德尔海的AABW的体积和性质如何以及为什么对风的变化做出反应。有了这一新的认识，我们将重新审视近几十年来观察到的广泛的AABW变暖和收缩，并为监测AABW环流未来变化的国际战略提供信息。

项目成果

Underwater ice boosts production of the world ocean's densest waters.

• DOI: 10.1126/sciadv.ade7006
• 发表时间: 2022-10-21
• 期刊: Science advances
• 影响因子: 13.6

Stabilization of dense Antarctic water supply to the Atlantic Ocean overturning circulation

• DOI: 10.1038/s41558-019-0561-2
• 发表时间: 2019-10-01
• 期刊: NATURE CLIMATE CHANGE
• 影响因子: 30.7
• 作者: Abrahamsen, E. Povl;Meijers, Andrew J. S.;Meredith, Michael P.
• 通讯作者: Meredith, Michael P.

Circulation, retention, and mixing of waters within the W eddell- S cotia C onfluence, S outhern O cean: The role of stratified T aylor columns

南大洋韦德尔-斯科舍交汇处的水的循环、滞留和混合：分层泰勒柱的作用

• DOI: 10.1002/2014jc010462
• 发表时间: 2015
• 期刊: Oceans
• 作者: Meredith M

Dense waters of the Weddell and Scotia Seas: recent changes in properties and circulation.

威德尔海和斯科舍海的稠密水域：性质和环流的最新变化。

• DOI: 10.1098/rsta.2013.0041
• 发表时间: 2014
• 期刊: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
• 作者: Meredith MP

Carbon storage shifts around Antarctica.

• DOI: 10.1038/s41467-022-31152-3
• 发表时间: 2022-06-14
• 期刊: NATURE COMMUNICATIONS
• 影响因子: 16.6
• 作者: Meredith, Michael P.