The Sunspot Observer - Average annual indices of solar activity - Solar activity in 1991 - April, 1991

Statistics of sunspot activity

April, 1991

Visual indices of solar activity by author's observations

Date	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	Average	%
W		135	179				211		178		337		317							222	147	109		42		111					180.73	100
Wn		85	100				112		82		137		207							74	63	30		0		25					83.18	46.03
Ws		50	79				99		96		200		110							148	84	79		42		86					97.55	53.97
n		3	5				10		10		14		10							12	7	7		3		8					8.09	100
A		0	0				1		3		4		0							6	2	2		1		2					1.91	23.60
B		0	1				4		1		3		2							2	2	3		1		3					2.00	24.72
C		0	1				0		1		1		1							0	0	1		0		1					0.55	6.74
D		0	1				3		3		2		2							0	1	0		0		0					1.09	13.48
E		2	2				0		0		2		1							2	1	0		0		0					0.91	11.24
F		0	0				0		0		0		0							1	0	0		0		0					0.09	1.12
G		1	0				1		0		1		1							0	0	0		0		0					0.36	4.49
H		0	0				1		1		1		1							1	0	0		1		0					0.55	6.74
I		0	0				0		1		0		2							0	1	1		0		2					0.64	7.87
x		0	1				5		4		7		2							8	4	5		2		5					3.91	48.31
r		0	0				0		1		1		1							0	1	0		0		0					0.36	4.49
s		0	1				3		4		2		5							2	0	2		1		3					2.09	25.84
a		1	0				2		1		2		0							1	2	0		0		0					0.82	10.11
h		0	1				0		0		0		0							0	0	0		0		0					0.09	1.12
k		2	2				0		0		2		2							1	0	0		0		0					0.82	10.11
x		0	0				2		5		5		3							7	3	3		2		4					3.09	38.20
o		1	2				6		5		5		4							2	2	4		0		3					3.09	38.20
i		2	2				1		0		4		1							2	2	0		1		1					1.45	17.98
c		0	1				1		0		0		2							1	0	0		0		0					0.45	5.62
CV		114	168				123		99		185		202							129	55	29		14		40					105.27	100
CVn		67	109				71		45		78		130							80	25	12		0		13					57.27	54.40
CVs		47	59				52		54		107		72							49	30	17		14		27					48.00	45.60