Effects of recent solar events on cosmic rays and Earth’s geomagnetic field

179-182Ground based worldwide network of neutron monitors (Kiel, Oulu, Moscow and Norilsk) recorded a large decrease in cosmic ray intensity following a major solar flare that was associated with sunspot region 1092 and occurred on the Sun on 1 August 2010. A major coronal mass ejection was also recorded on 30 July 2010. The present study suggests a definite effect of this solar event (1 August 2010) on the cosmic ray intensity variation along with large interplanetary changes. As a result, a large transient decrease in cosmic ray intensity has been observed. High values of solar wind speed, total IMF B, Bz, Dst and Ap have also been observed. The results of 1 August 2010 event have been compared with the recent solar event of 15 February 2011, which is associated with Forbusch decrease (FD) in cosmic ray but not associated with coronal mass ejection (CME). The study suggests that a strong solar flare alone is capable of producing FD. However, CME associated solar flare produce more disturbances in interplanetary medium as well as geomagnetic field