Vortices, waves, and energy cascades in atmospheric turbulence

大气湍流中的涡流、波和能量级联

• 批准号: RGPIN-2020-07001
• 负责人: Waite, Michael
• 金额: $ 4.44万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=743697
• 关键词: Vortices; waves; energy; cascades; atmospheric

Atmospheric fluid mechanics spans a wide range of length scale, from planetary scales down to millimetre scales. The mesoscale is an intermediate range of scales from kilometres to hundreds of kilometres; it supports an amazing variety of phenomena, including vortices, gravity waves, convective storms, and turbulence. Mesoscale dynamics play a key role in the energy budget of the atmosphere. Kinetic energy is primarily stored in large-scale vortices, and dissipated by very small-scale vortices; to reach the dissipation scales, energy must pass through the mesoscale. The transfers of energy between different scales in the mesoscale is called the mesoscale cascade. Despite its importance, this process is not completely understood and not fully captured by numerical weather prediction models. This research program aims to improve the representation of the mesoscale cascade in atmospheric models by gaining fundamental understanding of this process. There are three main objectives of this program: to understand the role of nonlinear waves and vortices in the mesoscale cascade; to quantify the exchanges of energy by different processes at different scales; and to improve the representation of small-scale turbulence in numerical models, especially localized upscale energy transfer. The work proposed here will deepen the fundamental understanding of atmospheric dynamics, improve the ability of numerical weather models to predict small-scale phenomena, and train students in atmosphere/ocean/climate dynamics and modelling, as well as for a variety of careers in computational modelling and data analysis.

大气流体力学的尺度范围很广，从行星尺度到毫米尺度。中尺度是一个从几公里到几百公里的中间尺度范围;它支持各种各样的现象，包括涡旋、重力波、对流风暴和湍流。中尺度动力学在大气能量收支中起着关键作用。动能主要储存在大尺度涡旋中，并由非常小尺度的涡旋耗散;为了达到耗散尺度，能量必须通过中尺度。中尺度下不同尺度之间的能量传递称为中尺度级联。尽管它的重要性，这一过程并没有完全理解，也没有完全捕捉到数值天气预报模型。该研究计划旨在通过对该过程的基本了解来改善大气模型中中尺度叶栅的表示。该计划有三个主要目标：了解非线性波和涡在中尺度叶栅中的作用;量化不同尺度下不同过程的能量交换;提高数值模型中小尺度湍流的代表性，特别是局部高档能量传递。这里提出的工作将加深对大气动力学的基本理解，提高数值天气模型预测小尺度现象的能力，并在大气/海洋/气候动力学和建模方面对学生进行培训，以及在计算建模和数据分析方面的各种职业。