The Origins of the Internal Wave Continuum: Wavenumber -frequency spectral diagnostics of forcing and energy transfer from new profiling platforms

内波连续体的起源：波数 - 来自新分析平台的强迫和能量传输的频谱诊断

• 批准号: 1129565
• 负责人: James Girton
• 金额: $ 44.83万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1129565&HistoricalAwards=false
• 关键词: Origins; Internal; Wave; Continuum; Wavenumber

Intellectual Merit: Internal waves propagate long distances to provide energy for mixing in remote locations. Intermittent breaking of internal waves generate a ubiquitous background energy throughout the global oceans. This background energy is believed to sustain the meridional ocean circulation. This global circulation transports warm surface waters from the equator to the poles, in exchange for cold, deep water. This exchange maintains the climate as we know it. A coordinated examination of approximately 20 recent moored profiler (MP) and moored acoustic Doppler current profiler (ADCP) deployments in a variety of forcing environments will evaluate the parameter dependencies of the wavenumber?frequency spectra of velocity, shear, and strain and the relationships between these internal wave spectra and mixing, as diagnosed from density overturns. In particular, the observed co-variability among the broadband continuum, the near-inertial peak, internal tidal peaks, and mixing/dissipation levels will be quantified to look for spring?neap modulation of the continuum level or near-inertial peak, an elevated continuum level during times of increased wind forcing, and variation in the performance of shear- and strain-based mixing parameterizations under different spectral shapes (beyond the typically-used metric of shear?strain ratio). While an initial description of each of the MP and ADCP records has been made and salient features in both frequency and wavenumber spectra described, a valuable opportunity exists for gaining additional insight by considering this complete collection of exciting new datasets in a single study.Broader Impacts: This research project will have important implications for the development of model parameterizations, such as being pursued by the Climate Process Team (CPT) on Internal Waves and Mixing. By clarifying the impact of different types of narrowband internal waves on the continuum spectral level and mixing rates, the investigators hope to narrow the field of viable processes that need to be considered, facilitating the development of effective mixing schemes for non-wave-resolving numerical models. In addition, part of the motivation for a detailed examination of the wavenumber?frequency spectrum using highly-resolved measurements in depth and time is to aid the interpretation of coarser datasets, such as those using half-inertial pairs or a burst-sampling mode. Such measurements, with profiling floats, ship-lowered instrumentation, and moorings, have the greatest potential to provide economical global coverage of internal wave and mixing information. This project will form the basis for Brian Chinn's graduate Ph.D. dissertation, contributing to the training of a talented new member of the ocean science workforce. Both principal investigators are active in graduate student advising through their affiliation with the University of Washington's School of Oceanography. Educational outreach will be conducted through a cooperative effort between the University of Washington and the Seattle Aquarium, which hosts regular community science events (COSEE-CL), with an emphasis on bringing basic information on internal waves and the importance of ocean mixing to a public forum.

智力优势：内波可以传播很长距离，为偏远地区的混合提供能量。内波的间歇性破裂在全球海洋中产生了普遍存在的背景能量。这种背景能量被认为支持了经向海洋环流。这种全球环流将温暖的表层水从赤道输送到两极，以换取冷水和深水。这种交换维持了我们所知的气候。对最近在不同强迫环境中部署的大约20个系泊剖面仪(MP)和系泊声学多普勒海流剖面仪(ADCP)进行协调检查，将评估速度、剪切和应变的波数频谱的参数依赖关系，以及这些内波谱和混合之间的关系，如从密度颠倒中诊断的。特别是，观测到的宽带连续层、近惯性峰、内潮汐峰值和混合/耗散层之间的协变性将被量化，以寻找连续层或近惯性峰的春季小潮调制、在风力增强时的连续层升高，以及基于剪切和应变的混合参数化在不同频谱形状下的性能变化(超出通常使用的剪切应变比度量)。虽然已经对每个MP和ADCP记录进行了初步描述，并描述了频率和波数谱中的显著特征，但通过在一项研究中考虑这一令人兴奋的新数据集的完整集合，存在着获得更多洞察的宝贵机会。广泛影响：这项研究项目将对模式参数的开发产生重要影响，例如气候过程小组(CPT)正在进行的关于内波和混合的研究。通过阐明不同类型的窄带内波对连续谱水平和混合率的影响，研究人员希望缩小需要考虑的可行过程的范围，促进为非波分辨数值模式开发有效的混合方案。此外，使用深度和时间的高分辨率测量对波数频谱进行详细检查的部分动机是为了帮助解释更粗略的数据集，例如使用半惯性对或突发采样模式的数据集。这种测量，加上剖面浮标、船下仪器和系泊设备，最有可能提供经济的全球内波和混合信息覆盖。该项目将为Brian Chinn的研究生博士论文奠定基础，为培养一名有才华的海洋科学工作者做出贡献。这两位主要研究人员都通过与华盛顿大学海洋学院的联系积极地为研究生提供咨询。将通过华盛顿大学和西雅图水族馆之间的合作努力开展教育宣传，西雅图水族馆定期举办社区科学活动(COSEE-CL)，重点是将关于内波和海洋混合的重要性的基本信息带到一个公共论坛上。