INTERPLANETARY AND SOLAR PLASMA PARAMETERS OF THE 14 JULY 2000 GROUND LEVEL ENHANCEMENT

Abstract

The ground level enhancement (GLE) of 14 July 2000 observed in the cosmic ray intensity has been examined. The event was recorded only by neutron monitors. It has a complex intensity-time structure. The northern hemisphere stations (Thule, Goose Bay, and Oulu) recorded abrupt increases earlier by 10 minutes than those in the southern hemisphere. Due to the difference in sensitivity at rigidity less than ~3 GV, the considered detectors recorded different increases in count rates relative to galactic cosmic ray background. This paper presents the study of GLE associated with the X5.7 solar flare. The rapid change of arriving particles were anisotropic during the onset of the event; it become isotropic during the declining phase of the event, where only low energy protons remained. In addition, the observations of energetic solar particles and interplanetary parameters have been examined.