Space-time features of solar cosmic ray penetration into high latitude regions of Earth's magnetosphere based on Intercosmos-19 satellite data

The penetration of solar cosmic rays into the upper latitude magnetosphere increased during the strong magnetic storm of 3-5 April 1979 (the maximum D_st variations was -197 nT at 01 UT on 4 April). The data were obtained from the Intercosmos-19 satellite at an altitude of about 500 km in the Northern Hemisphere in the afternoon and evening MLT sector and in the Southern Hemisphere at about 1,000 km in the morning to night sector. Solar cosmic ray proton penetration is studied along with the evolution of the high latitude electron capture boundary for various electron energies. During the storm: (1) the position of the penetration boundaries shifted toward the equator; (2) there was a variety of fluctuations in the location of the boundaries shifted toward the equator; (2) there was a variety of fluctuations in the location of the boundaries of the different penetration regions; and (3) rapid pulsations were observed for the penetrating particles on the day side of the magnetosphere close to the daytime polar cusp. The pulsation period of penetrating electrons of 15 to 20 sec correlates well with the fluctuations in the actual magnetic fluid.