External Power Supply to a Conductive Planet via Electromagnetic Induction

Abstract

The magnetic field variability of a young solar-type star delivers a time-varying magnetic flux to its hosted planets. In the case of early Earth prior to the establishment of the magne- tosphere, the associated electromotive force from a magnetically active young Sun would have facilitated the transfer of substantial inductive power, making it available to a nascent geodynamo during its poorly-understood initiation process. Herein a simple mechanism which creates favor- able conditions during the powering-up phase of a planetary dynamo is considered. Constraints on the amplitude of stellar-derived magnetic-flux variability are herein determined in order for a given amount of power to be transferred to a planetary body during an epoch of dynamo initiation. Astrophysical observations of the magnetic variability of young solar-type stars are accumulating but much uncertainty remains, even in our solar system case, as to the amount of inductive power transferred from the young Sun to any of its hosted planets. The shielding of a planetary interior by an early-developing magnetosphere could greatly reduce the effectiveness of this type of solar inductive power transfer as a means to initiate and/or reinforce dynamo action.