Trabalho de Conclusão de Curso de Graduação
Periodicidades no fluxo de raios cósmicos e análise de choques interplanetários
Autor
Vieira, Lucas Ramos
Institución
Resumen
Muons and neutrons that reach the Earth surface with high energy constitute a particles’ group called secondary cosmic rays. In order to study the flux of this particles data from muons and neutrons stations are used. The study of the periodicities in the neutron flux have obtained interesting results as, for instance, its anticorrelation with the sunspots number. In the year 2001 was installed at the Southern Space Observatory, in São Martinho da Serra, RS, the Multidirectional Muon Detector’s prototype (MMDP). In this Monograph it was looked for the periodicities embedded in the time series of the vertical detector MMDP’s data through the ARIST software in order to verify what kind of phenomena are responsible for the muon flux variations. Coronal mass ejections often propagate with speeds exceeding the solar wind speed driving interplanetary shocks. A significant number of the shocks are geoeffective, that is, cause moderate and intense geomagnetic storms. Another effect observed are the decreases in the cosmic rays flux, or the Forbush decreases (DF), recorded by surface detectors. The correlations between shock parameters and the intensity of the respective DF in the muons and neutrons flux observed by six detectors in 2001 data were investigated. It was verify that the speed, temperature, and magnetic field variations of the interplanetary medium caused by a shock wave were associated with cosmic rays decreases. The observed interplanetary medium density variations were not related with the DF.