Sigma-t is a quantity used in

oceanography Oceanography (), also known as oceanology, sea science, ocean science, and marine science, is the scientific study of the ocean, including its physics, chemistry, biology, and geology. It is an Earth science, which covers a wide range of to ...

to measure the

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 ...

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 ...

at a given temperature. σ_T is defined as ρ(S,T)-1000 kg m⁻³, where ρ(S,T) is the density of a sample of seawater at temperature T and salinity S, measured in kg m⁻³, at standard atmospheric pressure. For example, a water sample with a density of 1.027 g/cm³ has a σ_T value of 27.

References

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References

See also