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、潮汐和太阳强迫，但热量和洋流的最终分布取决于这些能量如何从大规模运动转移到小尺度，并在小范围内消散一些强迫能量。海洋表面的风通过密度波动逃逸到内部，称为近惯性波，波浪的另一个重要能源来自潮汐，当它遇到地形并产生内波时，称为内波。人们普遍认为，这两种类型的波在其他流动特征的催化下相互作用，并通过内波场将能量转移到更小尺度的运动和混合中。大规模强迫和其他催化剂，以及由此产生的预测搅拌，生成这些估计的第一个全球地图将有利于大规模海洋环流模型（OGCM），以及对这些搅拌过程的精确理解和参数化。内波能级联认识到次中尺度、OGCM 和气候建模者在同一会议上通常不会参加相同的科学会议，研究人员将在 2024 年组织一次联合会议，将这两个群体聚集在一起。海洋科学会议，重点关注全球模型中的内波和亚尺度参数化。该项目（麻州大学）将培训一名研究生。该团队的持续努力表明了他们对教育、推广、多样性和发展的承诺。 PI Sundermeyer 目前为五名女性研究生提供咨询，并将在该项目下寻求招募女性和/或代表性不足/少数族裔学生。 PI Sundermeyer 已在 Sandwich 的多个班级进行了多次关于海洋过程的演讲。在目前的项目中，他和研究生将与 Sandwich 和 New Bedford 公立学校的初中和高中教师合作，开发 PI Early 帮助设计和指导的海洋相关学习模块。 NSF-REU 项目并共同创立了 NWR​​A 早期科学家指导项目；PI Wortham 是西雅图太平洋科学中心的科学传播研究员；PI Lelong 是 MPOWIR 的导师，每年夏天都会积极参与 NWRA 西雅图分会。 Discovery Corps 是太平洋科学中心针对代表性不足社区的高中生和大学生的夏季研究项目。该提案涉及与 OGCM 建模师 H. Simmons 和墨西哥数学家 G. Simmons 的合作。埃尔南德斯-杜埃纳斯（Hernandez-Duenas）。海洋分层内部的内部波场主要从风和潮汐中获取能量，地转运动和地形散射充当催化剂，这种能量级联到小尺度并直接搅拌流体，产生涡旋模式。尽管观察表明在 O(10) km 尺度上的搅拌速率为 O(1) m2 s−1，但差距仍然存在。我们能够直接从能源预测这些尺度的扩散率，这项研究的第一个主要贡献是阐明相关过程在设定内波和涡旋谱的形状和强度方面的作用。通过考虑现实的分层和强迫，这项研究将弥补我们对海洋内波和涡旋模式场如何形成以及这些如何形成的理解上的重大差距。过程搅拌流体这里的工作还将通过量化从各种大规模强迫中提取能量的速率以及通过内部波场级联降级来帮助关闭海洋的能量预算。作为该级联的一部分自然产生的涡旋模场，这一结果在很大程度上仍然难以从现场观察中获得。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。