From the article, link to actual study and emphasis:
The study,Β led by Northwestern UniversityΒ and a team of international researchers, suggests that the magnetic field actually generates 20,000 miles below the surface. This was discovered after the team ran a series of complex calculations on a NASA supercomputer. Itβs worth noting that these are just initial findings and more research is required to confirm the data.
It's definitely going to be interesting to see the additional studies and findings that follow up because of this.