In oceanography, a halocline from Greek hals, halos 'salt' in addition to klinein 'to slope' is the cline, a subtype of chemocline caused by a strong, vertical salinity 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 add 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(a) regions, the vertical stratification is due to surface waters being warmer than deep waters in addition to the halocline is destabilizing. such(a) regions may be prone to salt fingering, a process which results in the preferential mixing of salinity.
Inhigh latitude regions such(a) 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 order 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 have vessel. whether 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 can coincide with a thermocline and pretend a pycnocline.
Haloclines are common in water-filled limestone caves nearly 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.
In the graphical representation, three layers can be discerned: