Interrelationships between Halo-Type Coronal Mass Ejections and Solar Flares Based on Observations in the 23rd and 24th Cycles

Solar activity of an explosive character during the 23rd and 24th cycles is analyzed. X-ray observations from the GOES-15 satellite during flares and observations during coronal mass ejections (CME) with the SOHO/LASCO coronagraph are used. The delay intervals between the onset of a flare and the onset of a Halo-type CME associated the same active region were analyzed. It is shown that the time interval between the onset of the flare and the onset of the CME is an average of 2 times shorter for flares in classes ≥ X1 than for less powerful flares. All events accompanied by powerful flares in classes ≥ X1 were examined separately. The interrelationship between Halo-type CME and the geomagnetic indices Kp and Dst, used for space weather forecasting, was evaluated. It is shown that the probability of a dangerous magnetic storm on the earth with Kp ≥ 7 is more than 80% if two conditions are met simultaneously: VCME ≥ 1000 km/s and |Dst| ≥ 100 nT.