Theoretical studies in the nonlinear dynamics of ocean currents, eddies and waves

洋流、涡流和波浪非线性动力学的理论研究

• 批准号: RGPIN-2015-05038
• 负责人: Swaters, Gordon
• 金额: $ 1.6万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613319
• 关键词: Theoretical; studies; nonlinear; dynamics; ocean

The ocean is a highly nonlinear turbulent caldron of ocean currents, eddies and waves that span time scales from minutes to years and space scales from centimetres to thousands of kilometres. Many of the physical processes observed in the ocean are not yet fully understood in terms of fundamental geophysical fluid dynamics. Discovering and deciphering the detailed dynamics of the ocean has the potential to make a profound impact on our ability to understand and predict the full range of dynamical responses that can occur as the environmental “drivers” of ocean physics change over time.  My long-term research objective is focused on discovering new dynamics and developing new physical insights into the fundamental nonlinear geophysical fluid mechanics of ocean currents, eddies and waves and to apply this new knowledge to understand existing and to predict new complex ocean flows. My research program exploits innovative theoretical models, mathematical analysis and computational simulations to describe and explain nonlinear oceanographic dynamical processes from the sub-mesoscale (e.g., internal gravity waves) to the mesoscale (e.g., baroclinic instability and eddy dynamics) to the basin scale (e.g., abyssal ocean circulation theory). Another objective of my research program is to predict where new or interesting physical oceanographic processes may be occurring in order to motivate further specific observational or numerical studies. I will address these objectives by: 1. Within the context of my research into abyssal ocean currents, I will (i) solve the important problem of the non-hydrostatic mixed Kelvin Helmholtz-frictional destabilization of abyssal overflows paying particular attention to describing the downslope flow, mixing and internal gravity wave generation properties; (ii) describe and clarify the role of baroclinic vortex stretching in the generation of surface-intensified mesoscale eddies associated with abyssal overflows; (iii) describe and clarify the role of dissipation and internal waves in the cross equatorial flow of abyssal ocean currents paying particular attention to predicting where in the equatorial Atlantic ocean these mixing processes are occurring,     2. Within the context of my research into nonlinear baroclinic instability, I will solve the very important and challenging problem of determining the nonlinear evolution of wave packets at the point of marginal stability when the background flow exhibits time variability. This research has the potential to make a groundbreaking advance in our understanding of the dynamics of nonlinear baroclinic waves and their role in large-scale mixing.  I will be training three MSc and two PhD students. In addition to making high-quality research contributions, my students learn highly desirable skills in formulating tractable research questions, logical reasoning, team work and computer programing and simulation.

海洋是一个高度非线性的洋流、漩涡和波浪的湍流大锅，其时间尺度从几分钟到几年，空间尺度从几厘米到几千公里。在海洋中观测到的许多物理过程，在基本的地球物理流体动力学方面还没有得到充分的理解。发现和破译海洋的详细动态有可能对我们理解和预测海洋物理学的环境“驱动因素”随时间变化而可能发生的各种动态反应的能力产生深远影响。 我的长期研究目标是专注于发现新的动力学和发展新的物理见解的基本非线性地球物理流体力学的洋流，漩涡和波浪，并应用这些新的知识来了解现有的和预测新的复杂的洋流。我的研究计划利用创新的理论模型，数学分析和计算模拟来描述和解释非线性海洋动力学过程从次中尺度（例如，内部重力波）到中尺度（例如，斜压不稳定性和涡动动力学）到盆地尺度（例如，深海环流理论）。我的研究计划的另一个目标是预测新的或有趣的物理海洋学过程可能会发生，以激励进一步具体的观测或数值研究。我将通过以下方式实现这些目标： 1.在我对深海洋流的研究范围内，我将㈠解决深海溢流的非流体静力混合开尔文-亥姆霍兹摩擦不稳定的重要问题，特别注意描述下坡流、混合和内部重力波产生特性;（ii）描述和澄清斜压涡旋伸展在地面-与深海溢流有关的中尺度涡旋加剧; ㈢说明和澄清耗散和内波在深海洋流的越赤道流动中的作用，特别注意预测这些混合过程在赤道大西洋的什么地方发生， 2.在非线性斜压不稳定的研究中，我将解决一个非常重要和具有挑战性的问题，即当背景气流表现出时变时，确定在边缘稳定点处波包的非线性演化，这一研究有可能在我们理解非线性斜压波的动力学及其在大尺度混合中的作用方面取得突破性的进展。 我将培养三名硕士生和两名博士生。除了做出高质量的研究贡献外，我的学生还将学习在制定易于处理的研究问题、逻辑推理、团队合作以及计算机编程和模拟方面的非常可取的技能。