Collaborative Research: Moored Observations of Turbulent Kinetic Energy Dissipation In and Below the Mixed Layer During VOCALS

合作研究：VOCALS 期间混合层内外湍流动能耗散的固定观测

• 批准号: 0745508
• 负责人: Robert Weller
• 金额: $ 45.47万
• 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: 2008
• 资助国家: 美国
• 起止时间: 2008-03-15 至 2012-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0745508&HistoricalAwards=false
• 关键词: Collaborative; Research; Moored; Observations; Turbulent

Intellectual merit: One goal of the VOCALS (VAMOS Ocean Cloud Atmosphere Land Study; VAMOS is Variability of the American Monsoon System) Regional Experiment (REx) is to improve understanding of the processes controlling sea surface temperature (SST) in the Southeastern Pacific off the west coast of South America. A connected set of upper-ocean processes --- near-inertial internal waves, mesoscale eddies, and vertical mixing --- are hypothesized to be important influences on the regional SST field. The relationship of eddies and near-inertial waves to SST, surface forcing and upper-ocean dissipation are of broader interest, but coincident observations of these processes are rare and exist only over periods of a few weeks.This collaborative project will study the relationship of upper-ocean dissipation, near-inertial internal waves, and mesoscale eddies to SST in the VOCALS-REx study region over a period of one year. The project involves the enhancement of an existing, heavily instrumented air-sea interaction mooring with instruments to measure turbulent kinetic energy dissipation at six depths in the upper ocean and analysis of these observations in the context provided by the mooring record. The primary focus of the proposed research is on understanding how physical processes in the upper ocean impact SST in the VOCALS study region, but the results will be of broader scientific interest, as the observations will be unique and will allow insight into some outstanding scientific questions. Specifically, the following will be examined: (i) the relationship of velocity, hydrography, and turbulent dissipation within eddies in the VOCALS region; (ii) the temperature balance of the mixed layer; (iii) near-inertial kinetic energy balance in the mixed layer; and (iv) the influence of near-inertial oscillations on SST. Broader Impact: There are no time series of turbulent kinetic energy dissipation and its vertical profile in the surface mixed layer of the deep ocean spanning an annual cycle. Recent advances in instrumentation, battery longevity, and data storage capacity make such measurements possible now. The dissipation measurements, combined with the existing moored measurements of surface forcing and detailed profiles of stratification and velocity, will allow unprecedented study of the energy balance of mixed-layer near-inertial oscillations and the temperature balance of the mixed layer over a period of one year. A subject of great interest to those interested in the global ocean energy balance is the relative amount of wind-forced mixed-layer near-inertial kinetic energy that is dissipated locally compared to the amount of near-inertial energy that propagates to the deep-ocean. The episodic nature of wind-forced inertial oscillations makes a long-term study of their energetics desirable and necessary, and this will be the first such study that can directly address the relative contributions of wave radiation and mixed-layer dissipation to the loss of mixed-layer near-inertial kinetic energy from the mixed layer.This project also has a significant educational and outreach component. Presently at Columbia University and Barnard College, a number of course offerings expose students to principles of oceanography and applications of advanced environmental field methods. Focused teaching modules on global ocean-atmosphere interaction science problems will be developed to be incorporated into curricula. During the planned work, our experiments will offer unique opportunities for the Lamont-Doherty Earth Observatory?s Summer Intern Program in which talented undergraduates from around the world work on problems related to all aspects of environmental sciences. Results will be presented to the public through Lamont-Doherty Earth Observatory's annual open house.

智力优点：VOCALS（VAMOS海洋云大气陆地研究; VAMOS是美国季风系统的可变性）区域实验（雷克斯）的一个目标是提高对控制南美洲西海岸东南太平洋海表温度（SST）的过程的理解。一组相互关联的上层海洋过程---近惯性内波，中尺度涡旋和垂直混合---被假设为对区域SST场的重要影响。涡旋和近惯性波与SST、表面强迫和上层海洋耗散的关系引起了广泛的兴趣，但对这些过程的同步观测很少，而且只存在几个星期的时间。该项目涉及加强现有的、装有大量仪器的海气相互作用系泊，用仪器测量上层海洋六个深度的湍流动能耗散，并在系泊记录提供的背景下分析这些观测结果。拟议研究的主要重点是了解上层海洋的物理过程如何影响VOCALS研究区域的SST，但结果将具有更广泛的科学意义，因为观测将是独特的，并将允许深入了解一些突出的科学问题。具体而言，将检查以下内容：（i）VOCALS区域中涡旋内的速度、水文和湍流耗散的关系;（ii）混合层的温度平衡;（iii）混合层中的近惯性动能平衡;以及（iv）近惯性振荡对SST的影响。更广泛的影响：深海表层混合层的湍动能耗散及其垂直廓线不存在跨越年周期的时间序列。在仪器、电池寿命和数据存储容量方面的最新进展使这种测量现在成为可能。耗散测量，结合现有的表面强迫和分层和速度的详细配置文件的系泊测量，将允许混合层近惯性振荡的能量平衡和混合层的温度平衡在一年内前所未有的研究。对全球海洋能量平衡感兴趣的人非常感兴趣的一个问题是，与传播到深海的近惯性能量相比，风强迫混合层近惯性动能在当地消散的相对数量。由于风强迫惯性振荡的偶发性质，对其能量学进行长期研究是可取和必要的，这将是第一个能够直接探讨波辐射和混合层耗散对混合层近惯性动能损失的相对贡献的研究，该项目还具有重要的教育和推广内容。目前在哥伦比亚大学和巴纳德学院，开设了一些课程，使学生了解海洋学原理和先进的环境实地方法的应用。将编制关于全球海洋-大气相互作用科学问题的重点教学单元，以纳入课程。在计划的工作中，我们的实验将为拉蒙特-多尔蒂地球观测站提供独特的机会。在这个暑期实习项目中，来自世界各地的有才华的本科生致力于解决与环境科学各个方面有关的问题。结果将通过拉蒙特-多尔蒂地球观测站的年度开放日向公众公布。