Search results
Results from the WOW.Com Content Network
Breaking swell waves at Hermosa Beach, California. A swell, also sometimes referred to as ground swell, in the context of an ocean, sea or lake, is a series of mechanical waves that propagate along the interface between water and air under the predominating influence of gravity, and thus are often referred to as surface gravity waves.
Depending on context, wave height may be defined in different ways: For a sine wave, the wave height H is twice the amplitude (i.e., the peak-to-peak amplitude): [1] =.; For a periodic wave, it is simply the difference between the maximum and minimum of the surface elevation z = η(x – c p t): [1] = {()} {()}, with c p the phase speed (or propagation speed) of the wave.
Fetch length, along with the wind speed (wind strength), and duration, determines the size of waves produced. If the wind direction is constant, the longer the fetch and the greater the wind speed, the more wind energy is transferred to the water surface and the larger the resulting sea state will be. [ 4 ]
It is measured in degrees (as on a compass), and often referred to in general directions, such as a NNW or SW swell. [1] Swell period is an important factor in surf forecasting. It is a measurement of time between successive waves in seconds. If you multiply the swell period by 1.5 you will calculate the speed in knots of the wave group for ...
Significant wave height H 1/3, or H s or H sig, as determined in the time domain, directly from the time series of the surface elevation, is defined as the average height of that one-third of the N measured waves having the greatest heights: [5] / = = where H m represents the individual wave heights, sorted into descending order of height as m increases from 1 to N.
The Douglas sea scale is a scale which measures the height of the waves and also measures the swell of the sea. The scale is very simple to follow and is expressed in one of 10 degrees. The scale is very simple to follow and is expressed in one of 10 degrees.
The Sverdrup relation can be derived from the linearized barotropic vorticity equation for steady motion: = / . Here is the geostrophic interior y-component (northward) and is the z-component (upward) of the water velocity.
The wave amplitude is a, the wavelength is denoted by λ (related to the wavenumber k by k = 2π / λ ), the gravitational acceleration by g and the phase speed by c p (with c p = Ω(k) / k ).