Editing Heat engine (section)

=== Earth's heat engine ===
Earth's [[atmosphere]] and [[hydrosphere]]—Earth's heat engine—are coupled processes that constantly even out solar heating imbalances through evaporation of surface water, convection, rainfall, winds and ocean circulation, when distributing heat around the globe.<ref name="Lindsey 2009">{{cite journal
|last=Lindsey
|first=Rebecca
|year=2009
|title=Climate and Earth's Energy Budget
|journal=NASA Earth Observatory
|url=http://earthobservatory.nasa.gov/Features/EnergyBalance/
}}</ref>

A [[Hadley cell]] is an example of a heat engine. It involves the rising of warm and moist air in the earth's equatorial region and the descent of colder air in the subtropics creating a thermally driven direct circulation, with consequent net production of kinetic energy.<ref>{{cite journal |author=Junling Huang and Michael B. McElroy|title=Contributions of the Hadley and Ferrel Circulations to the Energetics of the Atmosphere over the Past 32 Years|journal=Journal of Climate |issue=7 |volume=27 |pages=2656–2666 |year=2014 |doi=10.1175/jcli-d-13-00538.1|bibcode=2014JCli...27.2656H|s2cid=131132431 |doi-access=free }}</ref>