Question

How does the outer core affect earth?

Answer 1

Its movement is thought to create the Earth's magenteic fields.

Explanation:

Circulating magma in the molten outer core generates a weak magnetic field, which the researchers suspect may be leaking into the inner core and generating an electric current. The twisting force generated by this electromagnetic interaction may be what drives the inner core's rotation.

Song said the difference in rotation of the inner core could in turn affect the Earth's rotation and have implications for satellites, rockets and spaceships.
https://www.livescience.com/9313-earth-core-rotates-faster-surface-study-confirms.html

The liquid outer core is thought to create Earth's magnetic field through convection currents and the Coriolis effect. The magnetic field is 50 times stronger in the outer core than on the surface of the Earth. Scientists believe the solid inner core stabilizes the magnetic field produced in the outer core.
http://www.kids-earth-science.com/earths-core.html