Comparison of measurements of electromagnetic induction in the magnetosphere of Venus with laboratory simulations

Analysis of Venera 9 and 10 data suggest a comingled excitation of the ionosphere of Venus by the time dependent component of the interplanetary magnetic field, upon which may be super-imposed a contribution from the interplanetary electric field. The inductive contributions correspond respectively to generation of eddy currents and to unipolar induction, i.e., the TE and TM modes of classical electromagnetism. The former is suggested when the interplanetary magnetic field exhibits significant changes in intensity or orientation, but could also have contributions from fluctuations in plasma pressure expressed through the frozen-in field. Since the TM mode depends upon E=v _c ×B, the TM mode can also have an unsteady component. The magnetic field measured near Venus by Venera 9 and 10 is considered within this framework and with respect to laboratory simulation using both conducting and insulated (but internally conducting) spheres.