Statistics of sunspot activity
April, 1987
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 | 13.00 | 11.50 | 11.29 | 18.50 | 32.00 | 52.29 | 66.17 | 65.25 | 78.80 | 77.14 | 87.60 | 92.75 | 85.17 | 79.50 | 90.75 | 63.20 | 51.71 | 39.17 | 27.20 | 11.00 | 29.25 | 36.83 | 32.14 | 43.17 | 24.86 | 21.80 | 11.83 | 22.50 | 26.83 | 37.86 | 44.70 | 100 |
| Wn | 13.00 | 11.50 | 11.29 | 11.83 | 11.20 | 11.00 | 1.83 | 0.00 | 0.00 | 0.00 | 4.40 | 11.00 | 11.17 | 12.00 | 10.75 | 5.00 | 1.57 | 9.17 | 6.80 | 11.00 | 8.25 | 26.67 | 28.86 | 34.00 | 24.86 | 21.80 | 11.83 | 16.50 | 11.83 | 15.43 | 11.82 | 26.44 |
| Ws | 0.00 | 0.00 | 0.00 | 6.67 | 20.80 | 41.29 | 64.33 | 65.25 | 78.80 | 77.14 | 83.20 | 81.75 | 74.00 | 67.50 | 80.00 | 58.20 | 50.14 | 30.00 | 20.40 | 0.00 | 21.00 | 10.17 | 3.29 | 9.17 | 0.00 | 0.00 | 0.00 | 6.00 | 15.00 | 22.43 | 32.88 | 73.56 |
| n | 1.00 | 1.00 | 1.00 | 1.50 | 2.20 | 2.71 | 3.50 | 3.63 | 4.40 | 3.86 | 4.20 | 5.25 | 5.00 | 5.00 | 5.50 | 4.40 | 3.29 | 3.00 | 2.20 | 1.00 | 2.50 | 3.00 | 2.29 | 3.33 | 2.00 | 1.80 | 1.00 | 1.75 | 2.00 | 2.57 | 2.86 | 100 |
| A | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | 0.00 | 0.17 | 0.50 | 0.40 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.75 | 0.80 | 0.29 | 0.83 | 0.60 | 1.00 | 1.50 | 1.17 | 0.43 | 1.33 | 0.00 | 0.40 | 0.17 | 0.50 | 0.50 | 0.00 | 0.38 | 13.43 |
| B | 0.00 | 0.00 | 0.00 | 0.50 | 0.60 | 0.00 | 0.67 | 0.38 | 0.00 | 0.00 | 0.20 | 0.25 | 0.00 | 0.00 | 1.00 | 1.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 1.00 | 0.43 | 0.00 | 0.00 | 0.00 | 0.00 | 0.75 | 1.17 | 0.57 | 0.30 | 10.49 |
| C | 0.57 | 0.33 | 0.14 | 0.50 | 0.40 | 0.71 | 0.00 | 0.50 | 0.60 | 1.57 | 1.80 | 1.75 | 1.83 | 1.67 | 1.50 | 0.40 | 1.14 | 0.17 | 0.00 | 0.00 | 0.25 | 0.50 | 1.14 | 0.50 | 0.57 | 0.60 | 0.50 | 0.00 | 0.00 | 1.00 | 0.69 | 24.06 |
| D | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | 1.00 | 2.33 | 1.50 | 0.80 | 0.57 | 0.80 | 0.75 | 0.33 | 0.67 | 1.25 | 1.00 | 0.86 | 0.33 | 0.60 | 0.00 | 0.00 | 0.00 | 0.00 | 0.67 | 0.57 | 0.20 | 0.00 | 0.00 | 0.00 | 0.29 | 0.49 | 17.14 |
| E | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.13 | 0.00 | 0.43 | 0.60 | 0.50 | 0.33 | 0.33 | 0.00 | 0.00 | 0.00 | 0.67 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.10 | 3.48 |
| F | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | 0.00 | 0.17 | 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 | 0.01 | 0.43 |
| G | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.50 | 2.00 | 1.14 | 0.20 | 0.50 | 0.33 | 0.17 | 0.00 | 0.20 | 0.14 | 0.00 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.19 | 6.47 |
| H | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | 0.14 | 0.00 | 0.25 | 0.67 | 0.17 | 0.00 | 0.00 | 0.29 | 0.00 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.06 | 2.23 |
| I | 0.43 | 0.67 | 0.86 | 0.50 | 0.80 | 1.00 | 0.17 | 0.13 | 0.40 | 0.00 | 0.40 | 1.25 | 1.33 | 2.00 | 1.00 | 1.00 | 0.57 | 1.00 | 0.60 | 0.00 | 0.25 | 0.33 | 0.29 | 0.83 | 0.86 | 0.60 | 0.33 | 0.50 | 0.33 | 0.71 | 0.64 | 22.29 |
| x | 0.00 | 0.00 | 0.00 | 0.50 | 0.80 | 0.00 | 0.83 | 0.88 | 0.40 | 0.00 | 0.20 | 0.25 | 0.00 | 0.00 | 1.75 | 1.80 | 0.29 | 0.83 | 0.60 | 1.00 | 2.00 | 2.17 | 0.86 | 1.33 | 0.00 | 0.40 | 0.17 | 1.25 | 1.67 | 0.57 | 0.68 | 23.92 |
| r | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 0.20 | 0.29 | 0.00 | 0.00 | 0.00 | 0.50 | 0.17 | 0.71 | 0.33 | 0.57 | 0.40 | 0.17 | 0.50 | 0.17 | 1.00 | 0.19 | 6.81 |
| s | 0.86 | 1.00 | 1.00 | 0.83 | 0.80 | 1.57 | 1.17 | 1.25 | 2.60 | 1.86 | 1.80 | 1.25 | 1.67 | 2.67 | 1.50 | 1.20 | 0.71 | 1.00 | 0.80 | 0.00 | 0.00 | 0.67 | 0.71 | 1.33 | 0.86 | 0.80 | 0.67 | 0.00 | 0.17 | 0.86 | 1.05 | 36.79 |
| a | 0.00 | 0.00 | 0.00 | 0.17 | 0.40 | 0.86 | 0.33 | 0.50 | 0.40 | 0.57 | 0.80 | 2.00 | 1.83 | 1.33 | 0.75 | 0.20 | 1.14 | 0.33 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.57 | 0.20 | 0.00 | 0.00 | 0.00 | 0.14 | 0.43 | 14.99 |
| h | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.14 | 0.67 | 0.50 | 1.00 | 1.00 | 1.20 | 1.25 | 0.50 | 0.67 | 0.25 | 0.60 | 0.57 | 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 | 0.28 | 9.89 |
| k | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 0.50 | 0.00 | 0.43 | 0.20 | 0.50 | 1.00 | 0.33 | 0.75 | 0.40 | 0.29 | 0.83 | 0.80 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.22 | 7.61 |
| x | 0.43 | 0.67 | 0.86 | 0.50 | 1.00 | 1.00 | 0.33 | 0.63 | 1.00 | 0.14 | 0.40 | 1.50 | 2.00 | 2.17 | 1.75 | 1.80 | 1.14 | 1.83 | 1.40 | 1.00 | 1.75 | 1.50 | 0.71 | 2.17 | 0.86 | 1.00 | 0.50 | 1.00 | 0.83 | 0.71 | 1.09 | 37.94 |
| o | 0.57 | 0.33 | 0.14 | 1.00 | 1.20 | 0.86 | 2.00 | 2.50 | 3.40 | 3.00 | 2.00 | 3.00 | 2.50 | 2.00 | 3.00 | 2.40 | 1.29 | 0.50 | 0.40 | 0.00 | 0.75 | 1.17 | 1.57 | 1.17 | 1.14 | 0.80 | 0.50 | 0.75 | 1.17 | 1.71 | 1.43 | 49.86 |
| i | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.57 | 1.17 | 0.50 | 0.00 | 0.57 | 1.40 | 0.50 | 0.50 | 0.67 | 0.75 | 0.20 | 0.86 | 0.67 | 0.20 | 0.00 | 0.00 | 0.33 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.14 | 0.30 | 10.51 |
| c | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.29 | 0.00 | 0.00 | 0.00 | 0.14 | 0.40 | 0.25 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.05 | 1.68 |
| CV | 14.86 | 10.33 | 10.14 | 11.00 | 15.80 | 45.43 | 92.33 | 81.63 | 110.20 | 108.57 | 109.40 | 122.25 | 103.83 | 92.33 | 75.50 | 67.20 | 63.86 | 54.33 | 48.00 | 1.00 | 4.75 | 11.33 | 12.43 | 27.33 | 21.86 | 13.80 | 8.00 | 4.00 | 5.17 | 18.43 | 45.50 | 100 |
| CVn | 14.86 | 10.33 | 10.14 | 10.00 | 9.60 | 10.00 | 1.67 | 0.00 | 0.00 | 0.00 | 4.00 | 10.00 | 14.50 | 9.33 | 3.50 | 2.60 | 0.14 | 0.83 | 0.60 | 1.00 | 1.50 | 9.83 | 12.00 | 26.50 | 21.86 | 13.80 | 8.00 | 3.00 | 3.17 | 6.29 | 7.30 | 16.05 |
| CVs | 0.00 | 0.00 | 0.00 | 1.00 | 6.20 | 35.43 | 90.67 | 81.63 | 110.20 | 108.57 | 105.40 | 112.25 | 89.33 | 83.00 | 72.00 | 64.60 | 63.71 | 53.50 | 47.40 | 0.00 | 3.25 | 1.50 | 0.43 | 0.83 | 0.00 | 0.00 | 0.00 | 1.00 | 2.00 | 12.14 | 38.20 | 83.95 |
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