Solar Proton Event on September 23

MAKHMUTOV, V. S; BAZILEVSKAYA, G. A; RAULIN, J. -P; MARUN, A.

Rio de Janeiro

Congreso; 33rd International Cosmic Ray Conference (ICRC 2013); 2013

Sociedade Brasileira de Fisica

In this paper we focus on the signature ofthe solar proton event on January 23, 2012, as observed with the CARPET (KOVER) cosmic ray detector. This instrument was developed within an international cooperation between the Lebedev Physical Institute RAS (LPI; Russia), the Centro de Radio Astronomia e Astrofisica Mackenzie (CRAAM; Brazil) and the Complejo Astronomico el Leoncito (CASLEO; Argentina). The CARPET (KOVER) cosmic ray detector was installed on April 2006 at CASLEO at the Argentinean Andes (31.8S, 69.3W, h=2550 m, Rc=9.65 GV). We have analyzed cosmic ray variations observed by the GOES satellite instruments and by ground-based neutron monitor network (NMDB) during this event, as well as available solar and interplanetary medium observational data. We present and discuss the low ionosphere behavior under the impact of solar flare that occurred on January 23, 2012 and was followed by solar particles event. The ionosphere response to this solar phenomenon was detected using riometers (30 and 38.2 MHz) and VLF systems operating at the Comandante Ferraz Brazilian Station in Antarctica and at the Itapetinga Radio Observatory in São Paulo (Brazil). The results show that the low ionosphere was affected by this solar particles event, as evidenced by absorption observed in the cosmic noise and very low frequencies amplitude variation.