Fig. 4: Electrical conductivity for a BMO-driven dynamo and time evolution of the dynamo.
a, The solid lines represent the minimum electrical conductivity required for dynamo generation in BMOs in super-Earths. The x axis is the planetary mass Mp normalized by the Earth mass M⊕. The black, grey and light grey lines correspond to CMFs of 0.20, 0.32 and 0.68. The dashed lines and dashed-dotted lines represent the electrical conductivity based on equation (2) using the P and T condition at the CMB and the average P and T in the BMO. b, Time evolution of the magnetic field strength at the planetary surface as a function of time for a 6 M⊕ planet. The orange lines represent the BMO-driven dynamo, and the grey lines represent the core-driven dynamo. Details of the best fit, MLT, CIA and MAC are discussed in the main text.
