Investigation of the Cosmic Rays Associated with Ground Level Enhancement Events during Solar Cycle 24

Abstract

In the Sun, particles mostly protons (positively charged) with energies up to several hundred (MeV) are escaped during periods of intense flare activity. These particles are solar cosmic radiation, which are very small particles move at nearly the speed of light through space. The flare and coronal mass ejection (CME) may also cause a sharp rise in the cosmic ray intensity (CRI) at the Earth atmosphere. There are indications that the most energetic events occurred in the minimum phase of solar activity. When cosmic rays enter the Earth’s atmosphere they collide with atoms and molecules, as the Sun’s magnetic field became weak the cosmic rays are flooding into the solar system from deep space, causing health risks to space travelers. Sudden increases in the cosmic ray intensity called Ground level enhancements (GLEs) are measured or recorded on Earth’s sea level by neutron monitor (NM). The main objective of this research is to find the relation between cosmic ray and the GLE events and other solar activity parameters during the period years (2008-2019) for solar cycle (24). In this work satellite data of GLE based on ground level station Oulu NM (ONM) are taken is situated in north Finland at the height of 15m above sea level in the geographic coordinates (65.05°N; 25.47°E). The observational spectrum of two GLEs occurred during solar cycle 24 are investigated, one in 17 May 2012 which known as GLE71 and the other in 10 September 2017 as GLE72, in which the solar energetic particle was the larger in this solar cycle. Data of these two events indicate that the presence of different between them are due to populations of different energy spectrum, period of time occurrence, and increasing rate of (CRI).