On some characteristics of large kinetic energy coronal mass ejections during 1996-2015

We have studied the characteristics of large kinetic energy coronal mass ejections (LE-CMEs) (kinetic energy ≥1E + 31 ergs) observed between the time period years 1996-2015. During the study period, total 1250 CMEs occurred, which have their kinetic energy ≥1E + 31 ergs. Out of these 1250 events; only 314 events have proper acceleration, mass, kinetic energy and velocity, so other events are left out due to uncertainty or non availability of data. Out of 314 LE-CMEs there are 207 LE-CMEs those are not associated with solar flare events. Only 107 LE-CME events are associated with flares on solar disc. Our study shows that the average and the median linear speed of 314 LE-CMEs events are 835 km/s and 817 km/s, respectively. There are 197 LE-CMEs those are halo but we left out them from our study because of uncertainty in mass and energy. The angular widths of LE-CMEs for selected data set are less than ≤120° with a mean value of angular width as 84°. The mean value of mass and kinetic energy of LE-CMEs is 8.96E + 15 g and 2.38E + 31 ergs, respectively. The mean value of acceleration of large kinetic energy CMEs is 0.84 m/s2. It is also found that most of the events are biased towards acceleration that shows that large kinetic energy CMEs accelerate in general. The study also shows that 107 large kinetic energy CMEs associated with flares occurred when there is coronal holes (CH) in the nearby area and the mean distance between CMEs/ flares and the boundary of a coronal hole (CH) is 24°. We also find that mass and kinetic energy of CMEs do not depend on the location of CME and associated flare on the solar disc. It is also found that it is not necessary that energetic flares should associate with LE-CMEs.