Abstract
We study the temporal evolution of cosmic ray intensity during similar to 27-day Carrington rotation periods applying the method of superposed epoch analysis. We discuss about the average oscillations in the galactic cosmic ray intensity, as observed by ground based neutron monitors, during the course of Carrington rotation in low solar activity conditions and in different polarity states of the heliosphere (A < 0 and A > 0). During minimum and decreasing phases in low solar activity conditions, we compare the oscillation in one polarity state with that observed in other polarity state in similar phases of solar activity. We find difference in the evolution and amplitude of similar to 27-day variation during A < 0 and A > 0 epoch. We also compare the average variations in cosmic ray intensity with the simultaneous variations of solar wind parameters such as solar wind speed and interplanetary magnetic field strength. From the correlation analysis between the cosmic ray intensity and the solar wind speed during the course of Carrington rotation, we find that the correlation is stronger for A > 0 than A < 0.