Shell models in rapidly rotating dynamo systems" . ... We consider the main features of the spectra for various intensities of heat sources in the existing spherical models of convection and geodynamo and propose a simple shell model which can mimic some properties of the original dynamo system. ... M. Reshetnyak - United Institute of Physics of the Earth, Russian Academy of Scienc, 123995, Moscow, Russian Federation; e-mail: reshetnyak@ifz.ru ; . ...