A reference to both temperature and salinity of sea water: In oceanography, thermohaline circulation relates to the joint action or variations of temperature and salinity in a water mass.

A pattern of global ocean circulative currents or courses driven by density differences in water: The Gulf Stream is one example of thermohaline circulation that is created by variations or changes in temperature and salinity in the ocean.

The vertical movement of a layer of water caused by changes in the temperature-salinity relationship resulting in it becoming heavier than the water below it: Thermohaline convection is a kind of hydrodynamic instability and arrises due to one layer becoming colder or more saline, or both, and thus more dense.