Magnetostatic and electrostatic torques within a planet |
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| Authors: | Raymond Hide |
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| Institution: | Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK. E-mail: |
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| Abstract: | Several dynamic agencies control differential rotation between various regions of a rotating gravitating body such as a planet, namely advection of angular momentum (within fluid regions) and torques due not only to (a) viscous forces, (b) dynamic pressure forces and (c) gravitational forces, but also to (d) Lorentz forces (involving the flow of electric currents in electrically conducting regions), (e) magnetostatic forces (when magnetized material is present) and (f) electrostatic forces (due to the presence of electric charges). Torques due to (a), (b), (c) and (d) have already been treated in the literature, some extensively. It is of general theoretical interest to derive from first principles mathematical expressions for torques due to (e) and (f), even though they turn out to be quantitatively insignificant in the case of the Earth. |
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| Keywords: | Earth's core Earth's rotation electromagnetism geodynamics geomagnetism |
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