Editing Earth's magnetic field (section)

=== Effect of ocean tides ===
The oceans contribute to Earth's magnetic field. Seawater is an electrical conductor, and therefore interacts with the magnetic field. As the tides cycle around the ocean basins, the ocean water essentially tries to pull the geomagnetic field lines along. Because the salty water is only slightly conductive, the interaction is relatively weak: the strongest component is from the regular [[lunar tide]] that happens about twice per day (M2). Other contributions come from ocean swell, eddies, and even tsunamis.<ref name=NASA2016>{{cite web |url=https://svs.gsfc.nasa.gov/4541 |title=Ocean Tides and Magnetic Fields |publisher=Scientific Visualization Studio |date=2016-12-30 |website=NASA}} {{PD-notice}}</ref>

[[File:Global ocean magnetic field at sea level.webm|thumb|upright=1.7| Sea level magnetic fields observed by satellites (NASA)<ref name=NASA2016 />{{clarify|reason=Is it the entire field, or only the component attributed to tides?|date=January 2022}}]]

The strength of the interaction depends also on the temperature of the ocean water. The entire heat stored in the ocean can now be inferred from observations of the Earth's magnetic field.<ref>{{cite journal |doi = 10.1038/s41598-019-44397-8|title = Estimating global ocean heat content from tidal magnetic satellite observations|year = 2019|last1 = Irrgang|first1 = Christopher|last2 = Saynisch|first2 = Jan|last3 = Thomas|first3 = Maik|journal = Scientific Reports|volume = 9|issue = 1|page = 7893|pmid = 31133648|pmc = 6536534|bibcode = 2019NatSR...9.7893I}}</ref><ref name=NASA2016 />