On relation of the long period galactic cosmic rays intensity variations with the interplanetary magnetic field turbulence

We studX a relationship of the exponent gamma of the rigidity R spectrum delta D(R)/D(R) of the galactic cosmic rays (GCR) intensity variations (delta D(R)/D(R) proportional to R-gamma) the exponent nu(gamma) of the power spectral density (PSD) of the B-gamma component of the interplanetary magnetic field (IMF) (PSD = pf(-nu gamma), where P is power and f is frequency) in the range of the frequency f approximate to 4 x 10(-6)-10(-5) Hz. For this purpose we use data of neutron monitors and the IMF in the period of 1967-2002. We show that the rigidity spectrum of the long-period variations of the OCR intensity is hard in the minimum epochs of solar activity (gamma approximate to 0.6) when the exponent nu(gamma), of the PSD of the IMF is higher (nu(gamma) approximate to 1.9), and is soft in the maximum epochs (gamma approximate to 1.2), when the exponent vy is relatively lower (nu(gamma) approximate to 1.4). We ascribe these features to the essential rearrangement of the structure of the IMF turbulence during the 11-year cycle of solar activity assuming that the IMF turbulence is homogeneous and isotropy for time scales tau > 1 day. We reveal the relationships among rigidity spectrum exponent gamma, exponent nu(gamma) and the power P of the PSD of the IMF turbulence in different epochs of solar activity. We suppose that the changes of the structure of the IMF turbulence versus solar activity (manifesting in the changes of the exponent gamma of the rigidity R spectrum of the GCR intensity variations) is one of the important reasons of the 11-year variation of the OCR intensity for the rigidity of the OCR particles, to which neutron monitors are respond. (C) 2010 COSPAR. Published by Elsevier Ltd. All rights reserved.