The Feedback Dynamo of Mercury
Abstract
The observed weakness of the magnetic field of planet Mercury poses a long-standing puzzle to dynamo theory. Since Mercury is the closest planet to the Sun, it is subject to an intense solar wind flow. This leads to a relatively strong external magnetic field from the magnetosphere compared to the internal field. We explore the conjecture that a negative feedback process of magnetospheric origin could damp the dynamo evolution of Mercury. We present results from numerical dynamo simulations demonstrating how it is possible to capture the dynamo in a weak state in a powering up phase already with a weak external field. The numerical simulation enables us to show how the dynamics inside the inaccessible core are altered by the feedback and how the transition to a strong field dynamo is inhibited. We conclude with a description of the outside characteristics of the feedback dynamo, which can be compared to satellite data.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMGP51B..02H
- Keywords:
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- 1510 GEOMAGNETISM AND PALEOMAGNETISM / Dynamo: theories and simulations;
- 2756 MAGNETOSPHERIC PHYSICS / Planetary magnetospheres