A Correlative Study between Heliospheric Current Sheet Tilts, Cosmic Ray Intensities and Solar Activity Parameters

The correlations between the tilt angle (TA) of heliospheric current sheet (HCS) and the cosmic ray intensity (CRI), strength (B) of the interplanetary magnetic field (IMF), sunspot number (SSN), solar plasma speed (SWS) and density (n) have been studied before and after the reversal of IMF polarities. High sensitivity of the CRI of different rigidities to changes in the TA of HCS is observed during the qA < 0 epoch (when the IMF toward the Sun) as compared to the qA > 0 epoch (when IMF away from the Sun). The results of the present study are consistent with the drift model of cosmic rays, showing that the spectra of drift particles were harder after the reversal of IMF polarity state in (1999/2000). The reversal of IMF polarity state from (qA > 0 state to qA < 0 state) has a great effect on the rigidity-tilts dependence. The modulation of the lower energy particles of (median rigidity Rm < 22 GV) is more pronounced throughout qA < 0 epoch than that of qA > 0 epoch. The rate of sensitivity/modulation of CRIs to the HCS tilts is higher throughout the minimum solar activity years as compared to the maximum solar activity period.