Collaborative Research: Global estimates of energy pathways and stirring by internal waves and vortical mode

合作研究：能量路径的全球估计以及内波和涡旋模式的搅拌

• 批准号: 2123394
• 负责人: Miles Sundermeyer
• 金额: $ 39.62万
• 依托单位: University of Massachusetts, Dartmouth
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2123394&HistoricalAwards=false
• 关键词: Collaborative; Research; Global; estimates; energy

The ocean primarily derives its energy from large-scale wind, tidal and solar forcing, but the ultimate distribution of heat and currents depends on how this energy is transferred from large-scale motions to small scales where it is dissipated. Some of the energy forced by winds at the ocean surface escapes to the interior through density undulations, called near-inertial waves, that can span hundreds of kilometers. Another significant energy source for waves comes from the tide when it encounters topography and produces internal waves, known as the internal tide. It is generally well understood that these two types of waves interact, catalyzed by other flow features, and transfer energy through an internal wave field into smaller scale motions and mixing. This study will parameterize the spectrum of internal waves in terms of the large-scale forcing and other catalysts, and the predicted stirring that results, producing the first global maps of these estimates. Parameterizations of these stirring processes will benefit large-scale ocean general circulation models (OGCMs), and a refined understanding and parameterization of the internal wave energy cascade and its implications for vertical mixing and dissipation will benefit climate models. Recognizing that submesoscale, OGCM and climate modelers at the same meeting often do not attend the same scientific sessions, the investigators will bring these two communities together by organizing a joint session at the 2024 Ocean Sciences meeting, focused on internal wave and submesoscale parameterizations in global models. One graduate student will be trained under this project (UMassD). The ongoing efforts of the team demonstrates their commitment to education, outreach, diversity and inclusion. PI Sundermeyer currently advises (among others) five women graduate students, and will seek to recruit women and/or under- represented/minority students under this project. PI Sundermeyer has given several presentations on ocean processes to multiple classes in the Sandwich, MA public school district. Under the present project, he and the graduate student will work with middle and high school teachers in Sandwich and New Bedford public schools to develop ocean-related learning modules. PI Early helped design and mentor in an NSF-REU program and co-founded the NWRA early-scientist mentoring program; PI Wortham is a Science Communication Fellow at Seattle Pacific Science Center; PI Lelong is a mentor with MPOWIR and active in the Seattle Chapter of SWMS. NWRA participates every summer in Discovery Corps, the Pacific Science Center’s summer research program for high school and college students from under-represented communities. This proposal involves collaborations with OGCM modeler H. Simmons and with Mexican mathematician G. Hernandez-Duenas. The internal wave field in the stratified interior of the ocean draws its energy primarily from winds and tides, with geostrophic motions and topographic scattering acting as catalysts. This energy cascades to small scales and directly stirs the fluid, generating vortical mode along the way, which then itself contributes to energy transfers and stirring. Although observations indicate stirring rates of O(1) m2 s−1 at scales of O(10) km, gaps remain in our ability to predict diffusivity at these scales directly from the energy sources. The first major contribution of this study will be to clarify the roles of relevant processes in setting the shape and strength of the internal wave and vortical spectra. Second, it will extend previous theoretical and numerical estimates of stirring from internal waves and vortical mode to more realistic conditions. By considering realistic stratification and forcing, this study will close a significant gap in our understanding of how the oceanic internal wave and vortical mode fields are formed, and how these processes stir fluid at the submesoscale. The work here will also help close the energy budget for the ocean by quantifying the rate at which energy is extracted from various large-scale forcing, and cascaded downscale through the internal wave field. Last, it will quantify the shape and magnitude of the vortical mode field that arises naturally as part of this cascade, a result that has remained largely elusive from field observations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

海洋的能量主要来自大规模的风、潮汐和太阳能，但热量和洋流的最终分布取决于这种能量如何从大规模运动转移到小规模运动中，并在小规模运动中消散。海洋表面的风所产生的一些能量通过密度波动（称为近惯性波）逃逸到内部，这种波动可以跨越数百公里。波浪的另一个重要能量来源来自潮汐，当它遇到地形并产生内波时，称为内潮。通常很好地理解，这两种类型的波相互作用，由其他流动特征催化，并通过内部波场将能量传递到较小尺度的运动和混合中。这项研究将根据大尺度强迫和其他催化剂来参数化内波的频谱，以及预测的搅拌结果，产生这些估计的第一个全球地图。这些搅拌过程的参数化将有利于大尺度海洋环流模式（OGCM），而内部波能级联及其对垂直混合和耗散的影响的精确理解和参数化将有利于气候模式。认识到同一次会议上的次中尺度、OGCM和气候建模者往往不参加同一次科学会议，研究人员将在2024年海洋科学会议上组织一次联合会议，将这两个群体聚集在一起，重点讨论全球模型中的内波和次中尺度参数化。一名研究生将在该项目下接受培训。该小组的持续努力表明了他们对教育、外联、多样性和包容性的承诺。PI Sundermeyer目前为（除其他外）五名女研究生提供咨询，并将在该项目下寻求招募女性和/或代表不足/少数民族学生。PI Sundermeyer在马萨诸塞州三明治公立学区的多个班级做了几次关于海洋过程的演讲。根据目前的项目，他和研究生将与三明治和新贝德福德公立学校的初中和高中教师合作，开发与海洋有关的学习模块。PI早期帮助设计和导师在NSF-REU计划，并共同创立了NWRA早期科学家指导计划; PI沃瑟姆是科学传播研究员在西雅图太平洋科学中心; PI Lelong是一个导师与MPOWIR和活跃在SWMS的西雅图章。NWRA每年夏天都参加探索队，这是太平洋科学中心为来自代表性不足社区的高中生和大学生举办的夏季研究项目。该建议涉及与OGCM建模师H。西蒙斯和墨西哥数学家G. Hernana-Duenas海洋内部分层的内波场主要从风和潮汐中汲取能量，地转运动和地形散射起催化剂的作用。这种能量级联到小尺度并直接搅拌流体，沿着产生漩涡模式，然后本身有助于能量转移和搅拌。虽然观测表明在O（10）km尺度下的搅拌速率为O（1）m2 s−1，但我们直接从能源预测这些尺度下的扩散率的能力仍然存在差距。这项研究的第一个主要贡献将是澄清相关过程的作用，在设置的形状和强度的内波和涡谱。其次，它将扩展以前的理论和数值估计搅拌内波和涡模式更现实的条件。通过考虑现实的分层和强迫，这项研究将关闭一个显着的差距，我们的理解如何形成的海洋内波和涡模场，以及这些过程如何搅拌流体在亚中尺度。这里的工作还将通过量化从各种大尺度强迫中提取能量的速率来帮助关闭海洋的能量预算，并通过内部波场级联。最后，它将量化作为该级联的一部分自然产生的涡模场的形状和大小，这一结果在很大程度上仍然难以从现场观测中获得。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。