Collaborative Proposal: Moored Observations of Turbulent Kinetic Energy Dissipation in and below the Mixed Layer during VOCALS

知识价值：VOCALS （VAMOS海洋云大气陆地研究；VAMOS是美洲季风系统变率）区域实验（REx）的一个目标是提高对南美西海岸东南太平洋海面温度（SST）控制过程的理解。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——被假设是对区域海温场的重要影响。涡旋和近惯性波与海温、表面强迫和上层海洋耗散的关系具有更广泛的意义，但对这些过程的一致观测很少，而且只存在几个星期的周期。本合作项目将在为期一年的VOCALS-REx研究区内研究海洋上层耗散、近惯性内波和中尺度涡旋与海温的关系。该项目包括用仪器来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对这些观测结果进行分析，以增强现有的大量仪器的海气相互作用系泊。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研究区域的海温，但结果将具有更广泛的科学兴趣，因为观察结果将是独特的，并将允许洞察一些突出的科学问题。具体而言，将研究以下内容：(i) VOCALS区域涡旋内速度、水文和湍流耗散的关系；（ii）混合层的温度平衡；（iii）混合层近惯性动能平衡；近惯性振荡对海温的影响。更广泛的影响：深海表层混合层湍流动能耗散及其垂直剖面没有跨越年周期的时间序列。最近在仪器、电池寿命和数据存储容量方面的进步使这种测量成为可能。耗散测量，结合现有的地面强迫测量和分层和速度的详细剖面，将允许在一年内对混合层近惯性振荡的能量平衡和混合层的温度平衡进行前所未有的研究。对于那些对全球海洋能量平衡感兴趣的人来说，一个非常感兴趣的主题是风力驱动的混合层近惯性动能在局部耗散的相对量与传播到深海的近惯性动能的相对量。风激惯性振荡的偶发性使得对其能量学的长期研究是可取的和必要的，这将是第一个能够直接解决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。这个项目还有一个重要的教育和外联部分。目前，哥伦比亚大学和巴纳德学院开设了许多课程，让学生了解海洋学原理和先进环境领域方法的应用。将开发以全球海洋-大气相互作用科学问题为重点的教学模块，并将其纳入课程。在计划工作期间，我们的实验将为拉蒙特-多尔蒂地球天文台提供独特的机会。来自世界各地的有才华的本科生在这里研究与环境科学各个方面有关的问题。结果将通过拉蒙特-多尔蒂地球天文台的年度开放日向公众公布。

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.