Halocline Trance on:
[Wikipedia]
[Google]
[Amazon]
In
In the midlatitudes, an excess of evaporation over precipitation leads to surface waters being saltier than deep waters. In such regions, the vertical stratification is due to surface waters being warmer than deep waters and the halocline is destabilizing. Such regions may be prone to
In the graphical representation, three layers can be discerned:
* About of low salinity water "swimming" on top of the ocean. The temperature is , which is very near to the freezing point. This layer blocks heat transfer from the warmer, deeper levels into the sea ice, which has considerable effect on its thickness.
* About of steeply rising salinity and increasing temperature. This is the actual halocline.
* The deep layer with nearly constant salinity and slowly decreasing temperature.
oceanography
Oceanography (), also known as oceanology and ocean science, is the scientific study of the oceans. It is an Earth science, which covers a wide range of topics, including ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamic ...
, a halocline (from Greek ''hals'', ''halos'' 'salt' and ''klinein'' 'to slope') is a cline, a subtype of chemocline caused by a strong, vertical salinity
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...
gradient within a body of water. Because salinity (in concert with temperature) affects the density of seawater, it can play a role in its vertical stratification. Increasing salinity by one kg/m3 results in an increase of seawater density of around 0.7 kg/m3.
Description
In the midlatitudes, an excess of evaporation over precipitation leads to surface waters being saltier than deep waters. In such regions, the vertical stratification is due to surface waters being warmer than deep waters and the halocline is destabilizing. Such regions may be prone to salt fingering
Salt fingering is a mixing process, example of double diffusive instability, that occurs when relatively warm, salty water overlies relatively colder, fresher water. It is driven by the fact that heated water diffuses more readily than salty water ...
, a process which results in the preferential mixing of salinity.
In certain high latitude regions (such as the Arctic Ocean, Bering Sea
The Bering Sea (, ; rus, Бе́рингово мо́ре, r=Béringovo móre) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and The Ameri ...
, and the Southern Ocean) the surface waters are actually colder than the deep waters and the halocline is responsible for maintaining water column stability, isolating the surface waters from the deep waters. In these regions, the halocline is important in allowing for the formation of sea ice, and limiting the escape of carbon dioxide to the atmosphere.
Haloclines are also found in fjords, and poorly mixed estuaries where fresh water is deposited at the ocean surface.
A halocline can be easily created and observed in a drinking glass or other clear vessel. If fresh water is slowly poured over a quantity of salt water, using a spoon held horizontally at water-level to prevent mixing, a hazy interface layer, the halocline, will soon be visible due to the varying index of refraction
In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium.
The refractive index determines how much the path of light is bent, or ...
across the boundary.
A halocline is most commonly confused with a thermocline – a thermocline is an area within a body of water that marks a drastic change in temperature. A halocline can coincide with a thermocline and form a pycnocline.
Haloclines are common in water-filled limestone caves near the ocean. Less dense fresh water from the land forms a layer over salt water from the ocean. For underwater cave explorers, this can cause the optical illusion of air space in caverns. Passing through the halocline tends to stir up the layers.
Graph
In the graphical representation, three layers can be discerned:
* About of low salinity water "swimming" on top of the ocean. The temperature is , which is very near to the freezing point. This layer blocks heat transfer from the warmer, deeper levels into the sea ice, which has considerable effect on its thickness.
* About of steeply rising salinity and increasing temperature. This is the actual halocline.
* The deep layer with nearly constant salinity and slowly decreasing temperature.
Other types of clines
* Thermocline – A cline based on difference in water temperature, * Chemocline – A cline based on difference in waterchemistry
Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...
,
* Pycnocline – A cline based on difference in water density.
See also
* * * * * Thin layers (oceanography)References
{{authority control Aquatic ecology Physical oceanography Saline water