Mars' Paleomagnetic Field as the Result of a Single-Hemisphere Dynamo
Sabine Stanley,1*
Linda Elkins-Tanton,2
Maria T. Zuber,2
E. Marc Parmentier3
Mars' crustal magnetic field was most likely generated by dynamo
action in the planet's early history. Unexplained characteristics
of the field include its strength, concentration in the southern
hemisphere, and lack of correlation with any surface features
except for the hemispheric crustal dichotomy. We used numerical
dynamo modeling to demonstrate that the mechanisms proposed
to explain crustal dichotomy formation can result in a single-hemisphere
dynamo. This dynamo produces strong magnetic fields in only
the southern hemisphere. This magnetic field morphology can
explain why Mars' crustal magnetic field intensities are substantially
stronger in the southern hemisphere without relying on any postdynamo
mechanisms.
2 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
3 Department of Geological Sciences, Brown University, Providence, RI 02912, USA.
* To whom correspondence should be addressed. E-mail: stanley{at}physics.utoronto.ca
