INTeRnal waves In angular momeNtum StratifICation (INTRINSIC)

角动量分层中的内波（内在）

• 批准号: 2220343
• 负责人: Amit Tandon
• 金额: $ 48.07万
• 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: 2023
• 资助国家: 美国
• 起止时间: 2023-01-15 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2220343&HistoricalAwards=false
• 关键词: INTeRnal; waves; angular; momeNtum; StratifICation

This project will use a simplified model and a numerical model to examine how a 'rapid' change in water density that has a curved shape, a 'curved front', modifies the propagation and fate of internal gravity waves (IGW) within the ocean surface boundary layer. The investigators will determine if IGW energy increases or decreases within fine-scale fronts that are curved. They will test a new hypothesis that parametric subharmonic instability, initially proposed by Thomas and Taylor (2014) for geostrophic flow, is elevated within curved anticyclonic fronts. The research uses a hierarchy of fine-scale simulations, whereby analytical and idealized numerical models (least complex) are used to inform and facilitate analysis of realistic simulations (most complex).Present understanding of IGW propagation within fronts assumes a geostrophic balance. Although accurate for mesoscale fronts (horizontal scales of 50-200 km), fluid parcels within submesoscale fronts (horizontal scales of 0.1-10 km) often experience pronounced centripetal accelerations owing to frontal curvature. The combined principles of density, vorticity, and absolute angular momentum conservation have a profound influence on fluid parcel motion and modify the IGW dispersion relation. The proposed study advances the scientific community’s understanding of IGWs by examining the combined effects of these conservation laws in the context of semi-analytical, idealized and realistic fine-scale, numerical simulations heavily informed by observations. The expected outcomes of this research include improved understanding of the role of curved fronts on IGW dynamics and delineation of the limits of an analytical model.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.

该项目将使用简化的模型和数值模型来检查具有弯曲形状的“快速”的水密度变化，“弯曲的前部”如何修改海洋表面边界层内部重力波（IGW）的传播和命运。研究人员将确定IGW能量在弯曲的细尺度前线内是否增加或减少。他们将检验一个新的假设，即托马斯和泰勒（Thomas and Taylor，2014）最初提出的用于地球性流量的参数亚谐波不稳定性在弯曲的反气旋阵线中升高。该研究使用了精细模拟的层次结构，从而使用分析和理想化的数值模型（最小复杂）来告知和促进现实模拟的分析（最复杂）。对前部IGW繁殖的当前理解假定是地型平衡。尽管对于中尺度前沿（50-200 km的水平尺度），但在子尺度前沿（水平尺度为0.1-10 km）内的流体包裹经常经历由于额叶曲率而经历明显的中心置加速度。密度，涡度和绝对角动量保护的组合原理对流体包裹运动具有深远的影响，并修改了IGW分散性关系。拟议的研究通过在半分析，理想化和现实的精细尺度，数值模拟的背景下检查这些保护定律的综合效果，从而提高了科学界对IGW的理解。这项研究的预期结果包括对弯曲阵线在IGW动力学上的作用以及分析模型限制的划定的作用的理解得到了进一步的了解。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准来评估的支持。