Dynamics of Shelfbreak Processes and Shelf/Slope Exchange South of New England

新英格兰南部货架断裂过程和货架/斜坡交换的动态

• 批准号: 1657853
• 负责人: Glen Gawarkiewicz
• 金额: $ 27.95万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-15 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1657853&HistoricalAwards=false
• 关键词: Dynamics; Shelfbreak; Processes; Shelf; Slope

Recent studies have identified a significant warming trend in the shelf waters of the northwest Atlantic Ocean as well as extreme warming events such as during the first half of 2012. These have had major impacts on both the continental shelf ecosystem and commercial fisheries. It is unclear at this time how changing continental shelf water mass properties and circulation affect shelfbreak processes and shelf/slope exchange and how the exchange processes in turn modify shelf water masses. This project is the initial phase of a larger research plan originally devised to explore multiple exchange mechanisms involving the meandering of fronts, impingement of warm core rings and wind forcing. To address these issues of shelf/slope exchange, observations from the recently commissioned Ocean Observatories Initiative's Pioneer Array, other historical and recent hydrographic measurements, and remote sensing products will be analyzed. The investigators will also conduct process-oriented numerical modeling to investigate the dynamical mechanisms of dominant exchange processes and to quantify their relative contribution. The ultimate goal of the larger effort is to obtain sufficient understanding of shelf/slope exchange processes and their dependence on key frontal and forcing parameters. This one-year project will focus on assessing the quality and quantity of Pioneer Array data and demonstrating its scientific utility to resolve the exchange processes. The results from this study will be communicated to members of the commercial fishing industry through joint meetings with the Commercial Fisheries Research Foundation of Rhode Island. Results on the dynamics, frequency, and inter-annual variability of exchange processes will be shared with fisheries scientists of the National Marine Fisheries Service to gain insight into how shelf/slope exchange processes may be affecting living marine resources on seasonal and inter-annual time scales. Presentations will be made at various public venues to talk about the scientific results and their societal implications.It is hypothesized that i) shelfbreak frontal meanders, impingement of Gulf Stream warm-core rings, and wind forcing all induce significant cross-shelf exchange, and ii) these exchange processes are subject to the influences by the changing upstream, offshore, and atmospheric conditions over a broad range of time scales. . A recently developed theory for the most unstable wavelength and growth rate of finite amplitude meanders of a shelfbreak front will be validated against observations. Transports for streamers of shelf water that move offshore in the periphery of warm core rings will be quantified and compared to a recent scaling developed from laboratory experiments and limited observations. The Pioneer Array data along with other hydrographic data over the continental shelf, including data collected by commercial fishermen, will be used to investigate the frequency and cross-shelf penetration of subsurface intrusions of slope water or warm core ring water. A process-oriented regional model will be used for the dynamical analysis as well as data interpretation.

最近的研究发现，大西洋西北部大陆架沃茨出现了显著的变暖趋势，2012年上半年发生了极端变暖事件。这对大陆架生态系统和商业渔业都产生了重大影响。目前尚不清楚不断变化的大陆架水团特性和环流如何影响陆架断裂过程和陆架/陆坡交换，以及交换过程如何反过来改变陆架水团。这个项目是一个更大的研究计划的初始阶段，最初设计的目的是探索多种交换机制，涉及曲折的锋，温暖的核心环的冲击和风强迫。为了解决这些陆架/陆坡交换问题，将分析最近委托的海洋观测站倡议先锋阵列的观测结果、其他历史和最近的水文测量结果以及遥感产品。研究人员还将进行面向过程的数值模拟，以研究占主导地位的交换过程的动力学机制，并量化其相对贡献。更大的努力的最终目标是获得足够的理解大陆架/斜坡交换过程及其对关键的锋面和强迫参数的依赖。这个为期一年的项目将侧重于评估先锋阵列数据的质量和数量，并展示其在解决交换过程中的科学效用。这项研究的结果将通过与罗得岛商业渔业研究基金会的联席会议传达给商业渔业成员。关于交换过程的动态、频率和年际变化的结果将与国家海洋渔业局的渔业科学家分享，以深入了解陆架/陆坡交换过程如何在季节性和年际时间尺度上影响海洋生物资源。我们将在不同的公共场所发表演讲，讨论科学成果及其社会意义。我们假设：i）陆架断裂锋面弯曲，墨西哥湾流暖心环的撞击，以及风强迫都诱导了显著的跨陆架交换，以及ii）这些交换过程受到上游，近海和大气条件变化的影响。.最近发展的理论的最不稳定的波长和增长率的有限振幅曲折的一个shelfbreak前将验证对观测。运输的拖缆的大陆架水移动离岸的外围温暖的核心环将被量化，并比较最近的缩放从实验室实验和有限的观察。先锋阵列的数据沿着大陆架上的其他水文数据，包括商业渔民收集的数据，将用于调查斜坡水或暖核环水地下侵入的频率和跨大陆架渗透。一个面向过程的区域模型将用于动力分析和数据解释。

项目成果

Seasonal Evolution of Oceanic Upper Layer Processes in the Northern Bay of Bengal Following a Single Argo Float

一次 Argo 浮标后孟加拉湾北部海洋上层过程的季节演变

• DOI: 10.1029/2019gl082078
• 发表时间: 2019
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Shee, Abhijit;Sil, Sourav;Gangopadhyay, Avijit;Gawarkiewicz, Glen;Ravichandran, M.
• 通讯作者: Ravichandran, M.

How is New England Coastal Sea Level Related to the Atlantic Meridional Overturning Circulation at 26° N?

新英格兰沿海海平面与北纬 26° 的大西洋经向翻转环流有何关系？

• DOI: 10.1029/2019gl083073
• 发表时间: 2019
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Piecuch, Christopher G.;Dangendorf, Sönke;Gawarkiewicz, Glen G.;Little, Christopher M.;Ponte, Rui M.;Yang, Jiayan
• 通讯作者: Yang, Jiayan

Atmospheric and Offshore Forcing of Temperature Variability at the Shelf Break

• DOI: 10.5670/oceanog.2018.112
• 发表时间: 2018-03
• 期刊: Oceanography
• 影响因子: 2.8
• 作者: Ke Chen;G. Gawarkiewicz;A. Plueddemann

Gulf Stream Ring Water Intrusion on the Mid-Atlantic Bight Continental Shelf Break Affects Microbially Driven Carbon Cycling

• DOI: 10.3389/fmars.2019.00394
• 发表时间: 2019-07
• 期刊: Frontiers in Marine Science
• 影响因子: 3.7
• 作者: A. Hoarfrost;J. Balmonte;S. Ghobrial;Kai Ziervogel;J. Bane;G. Gawarkiewicz;C. Arnosti

Frontal Subduction of the Mid-Atlantic Bight Shelf Water at the Onshore Edge of a Warm-Core Ring

暖核环陆上边缘大西洋中部湾陆架水的锋面俯冲

• DOI: 10.1029/2018jc013794
• 发表时间: 2018
• 期刊: Journal of Geophysical Research: Oceans
• 作者: Zhang, Weifeng G.;Partida, Jacob
• 通讯作者: Partida, Jacob