Search results
Results From The WOW.Com Content Network
In fluid dynamics, gravity waves are waves in a fluid medium or at the interface between two media when the force of gravity or buoyancy tries to restore equilibrium. An example of such an interface is that between the atmosphere and the ocean, which gives rise to wind waves. A gravity wave results when fluid is displaced from a position of ...
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.
For the shown case, a bichromatic group of gravity waves on the surface of deep water, the group velocity is half the phase velocity. In this example, there are 5 + 3 / 4 waves between two wave group nodes in space, while there are 11 + 1 / 2 waves between two wave group nodes in time.
A geostrophic current may also be thought of as a rotating shallow water wave with a frequency of zero. The principle of geostrophy or geostrophic balance is useful to oceanographers because it allows them to infer ocean currents from measurements of the sea surface height (by combined satellite altimetry and gravimetry ) or from vertical ...
Very minute waves or ripples are not due to gravity but to capillary action, and have properties different from those of the longer ocean surface waves, [4] because the surface is increased in area by the ripples and the capillary forces are in this case large compared with the gravitational forces. [9]
The speed of all ocean waves is controlled by gravity, wavelength, and water depth. Most characteristics of ocean waves depend on the relationship between their wavelength and water depth. Wavelength determines the size of the orbits of water molecules within a wave, but water depth determines the shape of the orbits.
At the same time, but independently from Miles, Owen M. Phillips [10] (1957) developed his theory for the generation of waves based on the resonance between a fluctuating pressure field and surface waves. The main idea behind Phillips' theory is that this resonance mechanism causes the waves to grow when the length of the waves matches the ...
The interfacial movement between two layers of ocean is large compared to surface movement because although as with surface waves, the restoring force for internal waves and tides is still gravity, its effect is reduced because the densities of the two layers are relatively similar compared to the large density difference at the air-sea interface.