STUDY OF COSMIC RAY ANISOTROPY ALONGWITH INTERPLANETARY AND SOLAR WIND PLASMA PARAMETERS

摘要

Using the cosmic ray intensity data recorded with ground-based neutron monitor at Deep River has investigated taking into account the associated interplanetary magnetic field and solar wind plasma data during 1981-94. A large number of days having abnormally high/low amplitudes for successive number of five or more days as compared to annual average amplitude of diurnal anisotropy have been taken as high/low amplitude anisotropic wave train events (HAE/LAE). The results clearly indicate that the time of maximum of diurnal variation significantly remains in the 18-Hr direction for majority of the HAE/LAE cases. The phase of enhanced diurnal anisotropy shows a remarkable systematic shift towards later hours as compared to the co-rotational direction for some of the HAE cases, whereas it shows a remarkable systematic shift towards earlier hours for some of the LAE cases as compared to the co-rotational direction. The occurrence of these high/low amplitude events is found to be independent of the nature of the IMF polarity. The high-speed solar wind streams (HSSWSs) do not play any significant role in causing these types of events. The source responsible for these unusual anisotropic wave trains in CR has been proposed.