Geomagnetic Perturbations Caused by a Sphere Moving in the Conducting Liquid

We study the external magnetic-field perturbations caused by flows of a conducting incompressible liquid which streamlines a dielectric sphere moving in it. An analytical solution of the problem is obtained for the case of a potential flow of liquid and an arbitrary orientation of the external magnetic field. Angular distribution of the magnetic and electric field perturbations, as well as the dependence of their amplitudes on distance, are examined. The directions in which the magnetic and electric components of the perturbations are the maximum are determined. Temporal dependences and the spectra of electromagnetic signals are analyzed for different parameters of the problem. The results of analytical research are illustrated by numerical calculations.