在风力事件期间直接观察海岸产生的近惯性波
Samuel M Kelly1,2, Erica L Green1, Ian A Stokes3
1Large Lakes Observatory University of Minnesota Duluth Duluth MN USA.
概括
在上湖研究了风驱动的近惯性速度. 大多数能量以流的形式消散,但有些能量以海浪的形式在海上传播,可能会远程驱动混合.
科学领域:
- 物理海洋学 物理海洋学
- 流体动力学 流体动力学
- 沿海过程 沿海过程
背景情况:
- 输入的风能在海洋中产生接近惯性速度.
- 沿海的几何学显著影响这些近惯性运动的行为.
- 内部波对横向能量传输和在公海中混合至关重要.
研究的目的:
- 为了分析近惯性速度的动态,沿着一个直线海岸线在上湖.
- 研究沿海环境中风力驱动的近惯性波的产生,传播和能量消耗.
- 了解沿海地形在改变近惯性流动中的作用.
主要方法:
- 对速度,温度和流微观结构的深度概况的部署.
- 2018年8月在海上 (3-20公里) 进行96小时的重复调查.
- 使用1D动量方程来建模观察到的速度和动动能 (TKE) 剪切生产.
主要成果:
- 由风力工作 (2 mW/m^2) 产生的近惯性速度 (0.2 m/s) 被限制在距离海岸6公里的范围内.
- 观察到的TKE消散率 (1mW/m^2) 与TKE剪切生产的模型预测相匹配.
- 离岸传播的波浪携带的能量流量为10W/ (m-海岸线) 和下行流量为1mW/m^2.
结论:
- 近惯性风能主要是由于沿海地区的TKE剪切生产而丢失.
- 一部分的能量被转移到离岸传播的波浪中.
- 这些波浪可能会导致切割不稳定性和距离直近海岸线的地区的混合.
相关概念视频
Propagation of Waves
2.3K
When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
2.3K
Shock Waves
2.0K
While deriving the Doppler formula for the observed frequency of a sound wave, it is assumed that the speed of sound in the medium is greater than the source's speed through it. When this condition is breached, a shock wave occurs.
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high...
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high...
2.0K
Coriolis Force
3.1K
An accelerating particle experiences a force equal to the mass multiplied by the acceleration in an inertial frame of reference. Consider a particle in a non-inertial frame of reference, such as a sliding ball on a rotating table. The acceleration of the ball in this rotating reference frame is different than in the intertial frame, which modifies its equation of motion. The fictitious forces acting additionally on a rotating frame of reference alter Newton's Second Law expression.
3.1K
Modes of Standing Waves: II
835
The starting point for expressing the modes of standing waves is understanding the boundary conditions that the waves must follow. The boundary conditions are derived from the physical understanding of how the standing waves are sustained, that is, how the vibrating particles of the medium behave at the boundaries imposed on them.
For a tube open at one end and closed at the other filled with air, the modes are such that there is always an antinode at the open end and a node at the closed end....
For a tube open at one end and closed at the other filled with air, the modes are such that there is always an antinode at the open end and a node at the closed end....
835
Reflection of Waves
3.7K
When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at a distance from a cliff and hears the echo of their voice. The sound waves (longitudinal waves) traveling in the air are reflected from the bounding cliff. Similarly, flipping one end of a string whose other end is tied to a wall causes a pulse (transverse wave) to travel through the string, which gets reflected upon reaching the wall. In...
3.7K
Interference and Diffraction
31.9K
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
31.9K


