Cabbeling is when two separate water parcels mix to form a third which sinks below both parents. The combined water parcel is denser than the original two water parcels. The two parent water parcels may have the same

density Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...

, but they have different properties; for instance, different salinities and

temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...

s.Beer, Tom (1997). Environmental oceanography. Boca Raton: CRC Press. p. 123. , Section 5.4.3 Cabbeling. Seawater almost always gets denser if it gets ''either'' slightly colder ''or'' slightly saltier. But medium-warm, medium-salty water can be denser than both fresher, colder water and saltier, warmer water; in other words, the equation of state for

seawater Seawater, or sea water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has approximat ...

monotonic In mathematics, a monotonic function (or monotone function) is a function between ordered sets that preserves or reverses the given order. This concept first arose in calculus, and was later generalized to the more abstract setting of ord ...

, but

non-linear In mathematics and science, a nonlinear system (or a non-linear system) is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathe ...

. See diagram. Cabbeling may also occur in fresh water, since pure water is densest at about 4 °C (39 °F). A mixture of 1 °C water and 6 °C water, for instance, might have a temperature of 4 °C, making it denser than either parent. Ice is also less dense than water, so although ice floats in warm water, meltwater sinks in warm water. The densification of the new mixed water parcel is a result of a slight contraction upon mixing; a decrease in volume of the combined water parcel.AMS glossary
,. A new water parcel that has the same

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

, but is lower in

volume Volume is a measure of regions in three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch) ...

, will be denser. Denser water sinks or downwells in the otherwise neutral surface of the water body, where the two initial water parcels originated.

History of term

The importance of this process in oceanography was first pointed out by Witte, in a 1902 publication (). The German origin of the term has caused some

etymological Etymology ( ) is the study of the origin and evolution of words—including their constituent units of sound and meaning—across time. In the 21st century a subfield within linguistics, etymology has become a more rigorously scientific study. ...

confusion and disagreements as to the correct spelling of the term; for details, see the Wiktionary entry on cabelling. Oceanographers generally follow Stommel and refer to the process as "cabbeling".

High-latitude cabbeling

Cabbeling may occur in high incidence in high latitude waters.

Polar region The polar regions, also called the frigid zones or polar zones, of Earth are Earth's polar ice caps, the regions of the planet that surround its geographical poles (the North and South Poles), lying within the polar circles. These high latitu ...

waters are a place where cold and fresh water melting from

sea ice Sea ice arises as seawater freezes. Because ice is less density, dense than water, it floats on the ocean's surface (as does fresh water ice). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world' ...

meets warmer, saltier water.

Ocean currents An ocean current is a continuous, directed movement of seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours ...

are responsible for bringing this warmer, saltier water to higher latitudes, especially on the eastern shores of

Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...

continents, and on the western shores of Southern Hemisphere continents. The phenomenon of cabbeling has been particularly noted in the

Weddell Sea The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha C ...

Cabbeling in the Weddell Sea paper
. and the Greenland Sea.Cabbeling in the Greenland Basin paper
.

References

{{Wiktionary, cabbeling Oceanography Fluid mechanics Lakes Bodies of water