View source for Earth:Halothermal circulation

{{Short description|Part of world ocean circulation system}}
The term '''halothermal circulation''' refers to the part of the large-scale ocean circulation that is driven by global [[Density gradient|density gradient]]s created by surface heat and evaporation.''

The adjective halothermal derives from ''[[Earth:Salinity|halo-]]'' referring to salt content and ''-thermal'' referring to temperature, factors which together determine the [[Chemistry:Water (molecule)#Density of saltwater and ice|density of sea water]]. Halothermal circulation is driven primarily by salinity changes and secondarily by temperature changes (as opposed to the [[Earth:Thermohaline circulation|thermohaline]] mode in modern oceans). The generation of high salinity surface waters at low latitudes, which were therefore of higher density and thus sank, is thought to have been the dominant ocean circulation driver during [[Earth:Greenhouse and icehouse Earth|greenhouse climate]]s such as the [[Earth:Cretaceous|Cretaceous]]. Similar dynamics operate today in the Mediterranean.

The formation of bottom waters by halothermal dynamics is considered to be one to two orders of magnitude weaker than in thermohaline systems.

==References==
* Kennett, J.P. & Stott, L.D., 1990, Proteus and Proto-Oceanus, Paleogene oceans as revealed from Antarctic stable isotope results, ODP Leg 113. ''Proceedings Ocean Drilling Program, Science Results'' '''113''', 865–880.

{{physical oceanography}}

[[Category:Physical oceanography]]
[[Category:Geological processes]]

{{Sourceattribution|Halothermal circulation}}