The rigidity spectra for two consecutive Forbush effects (October--November 2003) of the galactic cosmic ray intensity estimated by use of the experimental data from neutron monitors are significantly different. The rigidity spectrum gradually hardens in the course of the first Forbush effect (October 22--28). On the contrary, it is very hard at the beginning of the second Forbush effect (October 29 to November 10). The rigidity spectrum progressively softens during the recovery phase of the galactic cosmic ray intensity. It is assumed that the peculiarities of the rigidity spectrum of the Forbush effects are related to the enhancement of the power within the energy range of the interplanetary magnetic field turbulence during the major phase of the Forbush effects. The additional large scale irregularities of the interplanetary magnetic field should be created due to the interaction of the extending high speed disturbances with the background solar wind. This assumption is confirmed by the analysis of the interplanetary magnetic field data. During the major phase of the Forbush effects the power spectral densities of the components of the interplanetary magnetic field are significantly larger than before and after the Forbush effects.

PACS numbers: 96.40.Cd, 96.50.Ci, 96.50.Fm