Turbulent oceans and atmospheres of the rotating planets: down to small scale

旋转行星的湍流海洋和大气：小到小尺度

• 批准号: RGPIN-2019-04957
• 负责人: Afanassiev, Iakov
• 金额: $ 2.19万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=737975
• 关键词: Turbulent; oceans; atmospheres; rotating; planets

The ability to predict climate is one of the vital problems in science. Climate systems include the Earth's oceans and atmosphere and are notoriously difficult to predict because of inherently turbulent nature of flows. My overall research objective is to better understand the dynamical processes that govern the behavior of the stratified and rotating fluids that comprise the Earth's oceans and atmosphere, as well as the atmospheres of other planets. Dynamical processes relevant to fluids on Earth are often similar to those on other planets. In this coming grant cycle the focus will be on thermal convection. This is a process which can be easily observed in your kitchen on small scale, yet it drives circulations of planetary atmospheres. Examples include bands and vortices on Jupiter and Saturn; wealth of data on these flows was recently provided by Juno and Cassini spacecrafts. Within an oceanographic context, our objective is to investigate turbulence at the range from the submeso-scale to a large-scale where the beta-effect is important. Mixing and the Lagrangian transport of tracers and drifters by turbulent motions of different scales are of particular interest. Our approach includes both theory and numerical simulations, and we also employ laboratory experiments to study geophysical flows. Our laboratory tank is less than two meters across but can be rotated fast around its axis. This setup allows us to create an idealized "ocean" or "atmosphere" of a rotating planet. We use a state-of-the-art measuring technique which we have been developing here in our lab. We call it the Altimetric Image Velocimetry. With this technique the data can be collected with precision and high resolution. Our laboratory tank can be thought of as an analogue computer where we can run numerous simulations/experiments with real fluid. The experiments do not require any assumptions which are routinely used in numerical simulations dealing with "virtual" fluid. This research will yield new results on the flows driven by convection and contribute to our understanding of nonlinear dynamics of turbulent oceans and atmospheres. The outcome of the proposed research will be of interest for oceanographic and atmospheric science communities who are working to include non-geostrophic dynamics in what traditionally have been quasi-geostrophic idealizations of ocean and atmosphere.

预测气候的能力是科学中的关键问题之一。气候系统包括地球的海洋和大气，众所周知，由于水流本身的湍流性质，气候系统很难预测。我的总体研究目标是更好地了解控制分层和旋转流体行为的动力学过程，这些流体组成地球的海洋和大气，以及其他行星的大气。与地球上的流体有关的动力学过程通常与其他行星上的类似。在即将到来的赠款周期中，重点将放在热对流上。这是一个在你的厨房里可以很容易地观察到的小范围的过程，但它驱动着行星大气的循环。例子包括木星和土星上的带和旋涡；朱诺号和卡西尼号宇宙飞船最近提供了大量关于这些流动的数据。在海洋学的背景下，我们的目标是研究从亚中尺度到大尺度的湍流，其中贝塔效应是重要的。通过不同尺度的湍流运动对示踪剂和漂浮物的混合和拉格朗日输送特别令人感兴趣。我们的方法包括理论和数值模拟，我们还利用实验室实验来研究地球物理流动。我们实验室的水箱直径不到两米，但可以绕其轴线快速旋转。这个装置允许我们创造一个理想的旋转行星的“海洋”或“大气”。我们使用一种最先进的测量技术，这是我们实验室一直在开发的。我们称之为高度计图像测速仪。利用该技术可以实现高精度、高分辨率的数据采集。我们的实验室水箱可以被认为是一台模拟计算机，在那里我们可以用真实的流体进行无数次模拟/实验。这些实验不需要任何常规用于处理“虚拟”流体的数值模拟中的假设。这项研究将对对流驱动的流动产生新的结果，并有助于我们理解湍流海洋和大气的非线性动力学。海洋和大气科学界正在努力将非地转动力学纳入传统上对海洋和大气的准地转理想化，拟议的研究结果将使他们感兴趣。