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 substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematicall ...

, but they have different properties; for instance, different

salinities 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 ...

and

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

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 salt 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 appro ...

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 order ...

, but

non-linear In mathematics and science, a nonlinear 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, mathematicians, and many other ...

. 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 property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different ele ...

, but is lower in

volume Volume is a measure of occupied 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 () The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the form of words a ...

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 the regions of the planet that surround its geographical poles (the North and South Poles), lying within the polar circles. These high latitudes are dominated by flo ...

waters are a place where cold and fresh water melting from

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

meets warmer, saltier water.

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

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 as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...

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 ...

Cabbeling in the Weddell Sea paper
. and the

Greenland Sea The Greenland Sea is a body of water that borders Greenland to the west, the Svalbard archipelago to the east, Fram Strait and the Arctic Ocean to the north, and the Norwegian Sea and Iceland to the south. The Greenland Sea is often defined a ...

.Cabbeling in the Greenland Basin paper
.

References

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