Halocline

Halocline

In oceanography, a halocline is a strong, vertical salinity gradient. 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.

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, a process which results in the preferential mixing of salinity.

In certain high latitude regions (such as the Arctic Ocean, Bering Sea, 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 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 is simply a region below the surface of a body of water where there is a significant increase or decrease in density. Density may be found by using the equation P=Mass/Volume(g/cm3)

ee also

* Isopycnal
* Pycnocline
* Thermocline


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Look at other dictionaries:

  • halocline — ● halocline nom féminin Couche à fort gradient vertical de salinité, immergée au voisinage de la thermocline et développée essentiellement entre 0 et 500 m de profondeur …   Encyclopédie Universelle

  • halocline — [hal′ə klīn΄] n. [ HALO + cline, as in ANTICLINE] a level of marked change, esp. increase, in the salinity of sea water at a certain depth …   English World dictionary

  • halocline — /hal euh kluyn /, n. a well defined vertical salinity gradient in ocean or other saline water. [1955 60; HALO + CLINE] * * * ▪ oceanography       vertical zone in the oceanic water column in which salinity changes rapidly with depth, located… …   Universalium

  • halocline —    A locally steep salinity gradient along the interface between fresh groundwater and saline ground water, such as is found at the base of the freshwater lens common beneath many limestone islands in the tropics. Water mixing and microbial… …   Lexicon of Cave and Karst Terminology

  • halocline — noun Date: 1960 a usually vertical gradient in salinity (as of the ocean) …   New Collegiate Dictionary

  • halocline — 1) the region of rapid change of salinity between two layers of different salinity. Analogous to the thermocline, q.v 2) a vertical gradient in the saltiness of the ocean …   Dictionary of ichthyology

  • halocline — n. [Gr. hals, salt, sea; klinein, to slope] That area of sharp vertical salinity change in the ocean or other saline water …   Dictionary of invertebrate zoology

  • halocline — noun a strong, vertical salinity gradient; the (sometimes indistinct) border between layers of water that contain different amounts of salt …   Wiktionary

  • halocline — hal·o·cline …   English syllables

  • halocline — hal•o•cline [[t]ˈhæl əˌklaɪn[/t]] n. oce a well defined vertical salinity gradient in ocean or other saline water • Etymology: 1955–60; halo +(thermo)cline …   From formal English to slang

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