Harmonics of high-amplitude wave trains in cosmic ray intensity

Using the ground based neutron monitor data of Deep River, the high-amplitude anisotropic wave train events (HAE) in cosmic ray intensity have been investigated during the period 1991-1994. It has been observed that the phase of diurnal anisotropy for majority of HAE shifts towards later hours; whereas it remains in the corotational/18-h direction for some of the HAE cases. Further, for majority of HAE cases the amplitude of diurnal and semi-diurnal anisotropy significantly deviates from the annual average values. The phase of semi-diurnal and tri-diurnal anisotropy for all HAE cases has shifted to later hours. Furthermore, for tri-diurnal anisotropy the amplitude remains statistically the same. The occurrence of HAE is unaffected by the nature of the Bz component of IMF polarity.