Collaborative Research: Kuroshio Extension System Study (KESS) Analysis - Mesoscale Processes

合作研究：黑潮扩展系统研究 (KESS) 分析 - 中尺度过程

• 批准号: 0851246
• 负责人: D. Randolph Watts
• 金额: $ 108.86万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0851246&HistoricalAwards=false
• 关键词: Collaborative; Research; Kuroshio; Extension; System

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The Kuroshio brings warm waters northward in an intense current along the western boundary of the North Pacific. The current departs the Japanese coast to flow eastward as the Kuroshio Extension. This strong jet creates a front between warm subtropical and cold northern waters of the Pacific. Several mechanisms are observed that drive mesoscale processes in the jet, and this variability in turn causes important changes in the regional circulation. A known recirculation gyre exists to the south of the jet, and another one to the north has been confirmed by the recent observations. The dynamic state of this system of circulations alternates on decadal time-scales between weakly meandering and vigorously meandering. Intellectual Merit: Variability in the upper and deep water column is coupled by mesoscale processes in a strong current. This leads to cross-frontal exchanges of heat, salt, and potential vorticity across the Kuroshio Extension, These exchanges in turn are thought to drive long-term changes in the strength and extent of the recirculation gyres. The Kuroshio Extension System Study (KESS) deployed a modern suite of moored instrumentation that spanned the water column, deployed profiling floats, and conducted intensive synoptic surveys and atmospheric soundings. The measurements, centered on the region of maximum mesoscale variability, present a window into mesoscale-driven cross-frontal exchange. The field program, May 2004-June 2006, fortuitously sampled during a regime-transition from weak to vigorous meandering. Initial analyses of KESS data reveal a process-rich circulation field: frontal waves nearly always propagate along the current axis, steep crests and troughs develop intermittently and rings detach to the north and south episodically. The observations highlighted the importance of interactions of deep variable currents with isolated seamounts in generating strong deep cyclones. The KESS data, plus atmospheric and remote-sensing data, will be combined with three state-of-the-art global ocean circulation models to understand the dynamics of mesoscale processes in the Kuroshio Extension. The main driving mechanisms to investigate, combining observations and models, include: 1) barotropic and baroclinic instabilities in the jet, such as frontal waves, steep meanders, rings and radiated waves and eddies; 2) interactions between strong deep eddies and seamounts; and 3) external perturbations upon the Kuroshio Extension from up- and downstream, such as westward propagating eddies and Rossby waves from the mid-Pacific. The important consequences to investigate, combining observations and models, include: 1) exchange of passive and dynamical water properties across the Kuroshio Extension front, caused by mesoscale processes; 2) the role of potential vorticity and momentum budgets in driving the recirculation gyres; 3) how regime shifts may arise from internal and external changes in potential vorticity structure of the Kuroshio Extension and recirculation gyre system.Broader Impacts: The Kuroshio Extension system plays an important role in subtropical-subpolar exchange, the strength of the recirculation gyre, the formation and distribution of mode waters, and the intensification and slowly varying location of the extra-tropical storm track across the North Pacific. An improved understanding of mesoscale dynamics is essential to guide the development and evaluation of global ocean models. A centralized KESS website (http://uskess.org) facilitates community outreach, acts as a data server, provides ready access to all publications, hosts data products such as movies of mapped and derived fields, and provides process-based metrics for numerical models. Three graduate students, a post-doc and a new PhD project scientist will be trained and mentored under this project. Two female undergraduate physics majors will conduct analyses for their senior projects and additional undergraduates will participate through summer REU programs. analyses for their senior projects and additional undergraduates will participate through summer REU programs.

该奖项是根据2009年的《美国复苏与再投资法》（第111-5号公法）资助的。黑发将北太平洋西部边界的强烈电流带到了温暖的水域。电流离开日本海岸，向东流动，作为黑发延伸。这款坚固的喷气式飞机在太平洋的温暖亚热带和冷北部水之间创造了一个前部。观察到几种机制可以驱动射流中的中尺度过程，而这种可变性又会导致区域循环的重要变化。射流的南部存在着一个已知的再循环Gyre，最近的观察结果证实了北部的另一个回旋。这种循环系统的动态状态在弱弯曲和剧烈曲折之间交替了衰老的时间表。智力优点：上水柱和深水柱的变异性与强电流中的中尺度过程相结合。这会导致热，盐和跨黑子延伸的潜在涡度的跨额外交换，而这些交换又被认为会导致再循环回旋的强度和程度的长期变化。黑发扩展系统研究（KESS）部署了一套现代的系泊仪器，该仪器跨越了水柱，部署了分析的浮子，并进行了密集的概要调查和大气声。这些测量值以最大中尺度变异性区域为中心，为中尺度驱动的跨额外交换提供了一个窗口。 2004年5月至2006年6月的现场计划在从弱弯曲到有力的曲折的政权过渡期间进行了偶然取样。 KESS数据的初步分析揭示了一个过程丰富的循环场：额波几乎总是沿着当前轴传播，陡峭的峰顶和槽间歇性地发育，并在北部和南方脱落。该观察结果突出了深度电流与孤立海舱相互作用在产生强大的深旋风中的重要性。 KESS数据以及大气和遥感数据将与三种最先进的全球循环模型相结合，以了解黑鲁希奥扩展中中尺度过程的动态。研究，结合观测和模型的主要驾驶机制包括：1）射流中的正压和压缩性不稳定性，例如额波，陡峭的蜿蜒曲折，环，辐射波和涡流； 2）强大的深层涡流和海拔之间的相互作用； 3）外部扰动在上游和下游，例如向西传播的涡流和中部太平洋的Rossby波。研究，结合观测和模型的重要后果包括：1）由中尺度工艺引起的在黑发延伸前横向的被动和动态水性质的交换； 2）潜在的涡度和动量预算在推动再循环回旋中的作用； 3) how regime shifts may arise from internal and external changes in potential vorticity structure of the Kuroshio Extension and recirculation gyre system.Broader Impacts: The Kuroshio Extension system plays an important role in subtropical-subpolar exchange, the strength of the recirculation gyre, the formation and distribution of mode waters, and the intensification and slowly varying location of the extra-tropical storm track across the North Pacific.对中尺度动力学的提高了解对于指导全球海洋模型的发展和评估至关重要。集中式KESS网站（http://uskess.org）促进了社区外展，充当数据服务器，可用访问所有出版物，托管数据产品，例如映射和派生字段的电影，并为数值模型提供基于过程的指标。该项目将接受三名研究生，一名博士后和新的博士学位科学家的培训和指导。两名女性本科生专业的专业将对他们的高级项目进行分析，而额外的本科生将通过夏季REU计划参加。对其高级项目和其他本科生的分析将通过夏季REU计划参加。