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Table 2 Earth-affecting events in solar cycles 23 and 24 in comparison with the SSN

From: Earth-affecting solar transients: a review of progresses in solar cycle 24

Property Cycle 23 Cycle 24 Change Change/SSN
SSN 81 49 − 39% 0%
Major flares (M&X) 1584 809 − 49% − 16%
X-class flares 128 49 − 62% − 37%
M-class flares 1456 760 − 48% − 14%
All CMEs (width ≥ 30°)a 8429c 8470 + 1% + 66%
Fast & wide CMEsa 501c 253 − 50% − 17%
Halo CMEsa 409c 323 − 21% + 30%
ICMEsb 307 208 − 32% + 12%
Magnetic clouds (MC) 114 86 − 25% + 25%
Ejecta (EJ) 193 122 − 37% + 4%
DH Type II bursts 339 181 − 47% − 12%
Large SEP events 102 46 − 55% − 26%
GLE events 16 2 − 88% − 79%
Magnetic storms (Dst < − 100 nT) 86 22 − 74% − 58%
CIR storms 11 2 − 82% − 70%
CME storms 75 20 − 73% − 56%
  1. aFrom the search engine in the CDAW catalog (http://www.lmsal.com/solarsoft/www_getcme_list.html)
  2. bFrom http://www.srl.caltech.edu/ACE/ASC/DATA/level3/icmetable2.htm
  3. cIncludes 223 Width ≥ 30° CMEs, 16 FW CMEs, and 13 halo CMEs estimated to have occurred during the 4-month SOHO/LASCO data gap