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

8429^c

8470

+ 1%

+ 66%

Fast & wide CMEs^a

501^c

253

− 50%

− 17%

Halo CMEs^a

409^c

323

− 21%

+ 30%

ICMEs^b

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%