Editing Sea surface temperature (section)

=== Extent of "surface" ===
{{See also|Ocean stratification|Photic zone}}
The extent of the ''ocean surface'' down into the ocean is influenced by the amount of mixing that takes place between the surface water and the deeper water. This depends on the temperature: in the tropics the warm surface layer of about 100&nbsp;m is quite stable and does not mix much with deeper water, while near the [[Polar regions of Earth|poles]] winter cooling and storms makes the surface layer denser and it mixes to great depth and then [[Ocean stratification|stratifies]] again in summer. This is why there is no simple single depth for ''ocean surface''. The [[Photic zone|photic depth of the ocean]] is typically about 100 m and is related to this heated surface layer. It can be up to around 200 m deep in the [[open ocean]].<ref name=":11">{{Cite book |last1=Emerson |first1=Steven |url=https://www.cambridge.org/core/product/identifier/9780511793202/type/book |title=Chemical Oceanography and the Marine Carbon Cycle |last2=Hedges |first2=John |date=2008-04-24 |publisher=Cambridge University Press |isbn=978-0-521-83313-4 |edition=1 |chapter=Chapter 4: Carbonate chemistry |doi=10.1017/cbo9780511793202}}</ref><ref name=":5">{{Cite book |last1=Chester |first1=R. |url=https://www.wiley.com/en-us/Marine+Geochemistry%2C+3rd+Edition-p-9781118349090 |title=Marine geochemistry |last2=Jickells |first2=Tim |date=2012 |publisher=Wiley/Blackwell |isbn=978-1-118-34909-0 |edition=3rd |location=Chichester, West Sussex, UK |chapter=Chapter 9: Nutrients, oxygen, organic carbon and the carbon cycle in seawater |oclc=781078031}}</ref>