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.

该项目将使用简化模型和数值模型来研究具有弯曲形状（“弯曲前沿”）的水密度的“快速”变化如何改变海洋表面内重力波（IGW）的传播和命运研究人员将确定 IGW 能量在弯曲的精细尺度锋面内是否增加或减少。他们将测试托马斯和泰勒 (2014) 最初针对地转流提出的参数次谐波不稳定性的新假设。该研究使用了精细尺度模拟的层次结构，其中分析和理想化数值模型（最简单）用于告知和促进实际模拟（最复杂）的分析。目前对IGW在锋面内传播的理解假设地转平衡虽然对于中尺度锋面（水平尺度为 50-200 公里）来说是准确的，但亚中尺度锋面（水平尺度为由于锋面曲率，密度、涡度和绝对角动量守恒的综合原理对流体团运动产生了深远的影响，并改变了 IGW 色散关系。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守恒定律的综合影响来理解 IGWs 这项研究的预期结果包括加深了对弯曲前沿对 IGW 动力学的作用的理解，并描绘了分析模型的局限性。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标准进行评估，被认为值得支持。