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

学术价值：声乐(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(REX)的目标之一是提高对南美洲西海岸东南太平洋海表面温度(SST)控制过程的理解。一系列相连的上层海洋过程-近惯性内波、中尺度涡旋和垂直混合-被假设为对区域SST场有重要影响。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人们的广泛关注，但对这些过程的一致观测很少，而且只存在几周的时间。本合作项目将在一年的时间里研究Voals-Rex研究区上层海洋耗散、近惯性内波和中尺度涡旋与SST的关系。该项目涉及利用仪器加强现有的海-气相互作用系泊设备，以测量上层海洋六个深度的湍动能耗散，并结合系泊记录所提供的情况分析这些观测结果。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声乐研究区域的SST，但其结果将具有更广泛的科学兴趣，因为观测将是独一无二的，并将使人们能够深入了解一些悬而未决的科学问题。具体地说，将研究以下内容：(I)声区涡旋内的速度、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；(Iv)近惯性振荡对海温的影响。更广泛的影响：深海表层混合层中不存在年周期的湍动能耗散时间序列及其垂直分布。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，结合现有的地面强迫系泊测量和层化和速度的详细剖面，将使人们能够史无前例地研究混合层近惯性振荡的能量平衡和一年期间混合层的温度平衡。那些对全球海洋能量平衡感兴趣的人非常感兴趣的一个主题是，与传播到深海的近惯性动能相比，当地耗散的风强迫混合层近惯性动能的相对量。风强迫惯性振荡的阶段性使得对其能量的长期研究是可取和必要的，这将是第一次能够直接解决波浪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此类研究。该项目还具有重要的教育和推广部分。目前，在哥伦比亚大学和巴纳德学院，许多课程让学生接触到海洋学原理和先进的环境野外方法的应用。将开发关于全球海洋-大气相互作用科学问题的重点教学单元，将其纳入课程。在计划的工作中，我们的实验将为拉蒙特-多尔蒂地球天文台-S暑期实习生计划提供独特的机会，来自世界各地的有才华的本科生将致力于解决与环境科学各方面有关的问题。结果将通过拉蒙特-多尔蒂地球天文台的年度开放参观向公众公布。

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.