Some Features of Solar Proton Events on March 7, 2011, and on February 20, 2014

The paper presents the results of studying two solar proton events—on March 7, 2011, and on February 20, 2014—which are associated with solar flares having almost the same power and located at close heliolongitudes, on the western side of the solar disk. The work was done on the basis of the experimental data obtained from the ACE spacecraft and the GOES artificial Earth satellites, located in the interplanetary space at the L1 point and inside the Earth’s magnetosphere on the geostationary orbit, respectively. A comparative analysis of the features of time profiles of solar energetic proton fluxes and variations of the interplanetary medium parameters is carried out. These parameters included the speed and density of the solar wind and the magnitude and direction of the interplanetary magnetic field. The main distinctions in the time profiles of proton fluxes of two solar events are shown to be related with the features of the interplanetary medium state on March 7, 2011, and on February 20, 2014. The results of a comparative analysis of time variations of solar proton fluxes with E > 10 and E > 30 MeV and of the Bz- and Bx-components of the interplanetary magnetic field on February 20, 2014, testify to the determining role of the interplanetary magnetic field’s structure in the formation of the features of time profiles of particle fluxes in the given event.