Abstract :
We have analyzed asymmetric cosmic ray intensity decreases ≥4%, observed during the period of 1997 to 2013 with coronal mass ejections and X-Ray solar flares. We have found total numbers of symmetric cosmic ray intensity decreases are 47. We have the data of CMEs for 42 events out of these, 27 symmetric cosmic ray intensity decreases (Fds) have been found to be associated with coronal mass ejections. The association rate of halo and partial halo CMEs are 48.15% and 51.85 % respectively. Further we have observed that 42 symmetric cosmic ray intensity decreases, are associated with X ray solar flares of different categories and majority of the associated solar flares are C-Class X-ray solar flares. From the study of symmetric cosmic ray intensity decreases with speed of associated CMEs, we found that the magnitude of symmertic cosmic ray intensity decreases and speed of CMEs are positively correlated with correlation coefficient 0.19.
Keyword :
: Coronal mass ejections, X-ray Solar flares, symmetric cosmic ray intensity decreases.