Statistics of sunspot activity
April, 1997
Visual indices of solar activity by National Geophysical Data Center
| Date | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | Average | % |
| W | 22.75 | 42.00 | 44.75 | 36.80 | 35.00 | 27.80 | 15.20 | 20.00 | 24.33 | 40.50 | 31.33 | 18.75 | 32.00 | 33.75 | 39.25 | 33.00 | 23.33 | 12.50 | 20.33 | 0.00 | 0.00 | 11.00 | 12.00 | 12.00 | 12.00 | 26.67 | 19.75 | 17.00 | 11.50 | 0.00 | 22.51 | 100 |
| Wn | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 10.33 | 28.75 | 18.33 | 15.00 | 13.50 | 5.50 | 0.00 | 0.00 | 4.00 | 0.00 | 12.00 | 0.00 | 0.00 | 11.00 | 12.00 | 12.00 | 12.00 | 9.00 | 3.00 | 0.00 | 0.00 | 0.00 | 5.55 | 24.64 |
| Ws | 22.75 | 42.00 | 44.75 | 36.80 | 35.00 | 27.80 | 15.20 | 20.00 | 14.00 | 11.75 | 13.00 | 3.75 | 18.50 | 28.25 | 39.25 | 33.00 | 19.33 | 12.50 | 8.33 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 17.67 | 16.75 | 17.00 | 11.50 | 0.00 | 16.96 | 75.36 |
| n | 1.00 | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 | 1.00 | 1.50 | 1.67 | 2.50 | 2.00 | 1.25 | 2.00 | 2.00 | 2.00 | 2.00 | 1.67 | 1.00 | 1.67 | 0.00 | 0.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.67 | 1.25 | 1.00 | 1.00 | 0.00 | 1.41 | 100 |
| A | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.60 | 0.00 | 0.25 | 0.00 | 1.50 | 0.33 | 0.00 | 0.25 | 0.50 | 0.00 | 0.00 | 0.33 | 0.25 | 1.00 | 0.00 | 0.00 | 1.00 | 0.33 | 0.50 | 0.33 | 0.00 | 0.25 | 0.00 | 1.00 | 0.00 | 0.28 | 20.00 |
| B | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.25 | 1.00 | 0.00 | 0.67 | 0.25 | 0.25 | 0.25 | 0.25 | 0.00 | 1.33 | 0.75 | 0.67 | 0.00 | 0.00 | 0.00 | 0.67 | 0.50 | 0.67 | 1.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.28 | 20.16 |
| C | 0.50 | 0.50 | 1.00 | 1.40 | 1.60 | 0.80 | 0.80 | 1.00 | 0.67 | 0.00 | 0.00 | 1.00 | 0.50 | 0.25 | 0.25 | 0.25 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.67 | 1.00 | 1.00 | 0.00 | 0.00 | 0.44 | 31.26 |
| D | 0.25 | 0.00 | 0.25 | 0.60 | 0.40 | 0.20 | 0.00 | 0.00 | 0.00 | 1.00 | 1.00 | 0.00 | 0.75 | 1.00 | 0.75 | 1.50 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.26 | 18.26 |
| E | 0.00 | 0.50 | 0.25 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.03 | 1.78 |
| F | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| G | 0.25 | 0.00 | 0.50 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.75 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.05 | 3.56 |
| H | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| I | 0.00 | 1.00 | 0.00 | 0.00 | 0.00 | 0.40 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.25 | 0.00 | 0.00 | 0.25 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.07 | 4.98 |
| x | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.60 | 0.00 | 0.50 | 1.00 | 1.50 | 1.00 | 0.25 | 0.50 | 0.75 | 0.25 | 0.00 | 1.67 | 1.00 | 1.67 | 0.00 | 0.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 0.25 | 0.00 | 1.00 | 0.00 | 0.56 | 40.16 |
| r | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | 0.60 | 0.25 | 0.67 | 0.00 | 0.00 | 0.00 | 0.00 | 0.25 | 0.25 | 0.25 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.67 | 0.50 | 0.67 | 0.00 | 0.00 | 0.14 | 10.20 |
| s | 0.25 | 1.00 | 0.25 | 0.60 | 1.20 | 0.60 | 0.00 | 0.00 | 0.00 | 0.50 | 0.00 | 0.50 | 1.25 | 0.25 | 0.50 | 0.75 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 0.33 | 0.00 | 0.00 | 0.28 | 20.12 |
| a | 0.75 | 1.00 | 1.75 | 1.40 | 0.80 | 0.60 | 0.40 | 0.75 | 0.00 | 0.50 | 1.00 | 0.50 | 0.25 | 0.75 | 0.75 | 0.75 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.40 | 28.34 |
| h | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.25 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.01 | 0.59 |
| k | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.25 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.01 | 0.59 |
| x | 0.00 | 1.00 | 0.00 | 0.00 | 0.00 | 1.00 | 0.20 | 0.25 | 0.00 | 1.50 | 0.33 | 0.00 | 0.50 | 0.50 | 0.00 | 0.25 | 0.33 | 0.25 | 1.00 | 0.00 | 0.00 | 1.00 | 0.33 | 0.50 | 0.33 | 0.00 | 0.25 | 0.00 | 1.00 | 0.00 | 0.35 | 24.98 |
| o | 1.00 | 0.50 | 1.75 | 1.80 | 2.00 | 1.00 | 0.80 | 1.25 | 1.67 | 1.00 | 1.67 | 1.25 | 1.50 | 1.50 | 1.75 | 1.25 | 1.33 | 0.75 | 0.67 | 0.00 | 0.00 | 0.00 | 0.67 | 0.50 | 0.67 | 1.67 | 1.00 | 1.00 | 0.00 | 0.00 | 1.00 | 70.99 |
| i | 0.00 | 0.50 | 0.25 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.25 | 0.50 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.06 | 4.03 |
| c | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| CV | 15.25 | 25.50 | 29.25 | 25.60 | 24.00 | 14.80 | 6.00 | 8.00 | 5.33 | 23.50 | 20.67 | 10.00 | 26.75 | 22.75 | 40.75 | 44.25 | 3.00 | 1.75 | 2.33 | 0.00 | 0.00 | 1.00 | 1.67 | 1.50 | 1.67 | 5.33 | 8.25 | 7.00 | 1.00 | 0.00 | 12.56 | 100 |
| CVn | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 3.33 | 22.50 | 19.00 | 9.50 | 5.25 | 0.50 | 0.00 | 0.00 | 0.67 | 0.00 | 1.33 | 0.00 | 0.00 | 1.00 | 1.67 | 1.50 | 1.67 | 1.33 | 0.25 | 0.00 | 0.00 | 0.00 | 2.32 | 18.44 |
| CVs | 15.25 | 25.50 | 29.25 | 25.60 | 24.00 | 14.80 | 6.00 | 8.00 | 2.00 | 1.00 | 1.67 | 0.50 | 21.50 | 22.25 | 40.75 | 44.25 | 2.33 | 1.75 | 1.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 4.00 | 8.00 | 7.00 | 1.00 | 0.00 | 10.25 | 81.56 |
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