Unusually low/high-amplitude anisotropic wave train events in cosmic-ray intensity as an effect of interplanetary turbulences

Abstract

Using the ground-based neutron monitor data of Deep River we have studied the low- and high-amplitude aniso-tropic wave train events (LAE/HAE) in cosmic-ray intensity for different latitudes. The investigation has been made for both LAE and HAE during the period 19811994. It has been observed that the phase of diurnal aniso-tropy in the majority of HAE/LAE cases remains in the same co-rotational direction, but has shifted to later hours in some HAE cases and to early hours in some LAE cases. Further, for majority of HAE/LAE cases, the ampli-tude of semi-diurnal anisotropy remains statistically the same, while the phase for all HAE cases shifted to later hours. The HAE appears dominant during the declining phase of solar activity, whereas LAE appears dominant during minimum solar activity.