Statistics of sunspot activity
December, 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 | 31 | Average | % |
| W | 18.57 | 23.00 | 25.80 | 19.50 | 17.83 | 23.67 | 37.83 | 44.20 | 38.83 | 36.50 | 23.67 | 24.33 | 20.00 | 29.25 | 37.25 | 40.80 | 36.40 | 39.60 | 34.60 | 29.20 | 13.20 | 18.17 | 20.80 | 12.83 | 27.00 | 31.17 | 27.83 | 34.33 | 37.33 | 45.00 | 39.50 | 29.29 | 100 |
| Wn | 3.14 | 4.40 | 5.00 | 3.25 | 0.00 | 0.00 | 15.00 | 12.20 | 0.00 | 2.75 | 3.67 | 8.67 | 4.00 | 0.00 | 0.00 | 0.00 | 4.60 | 12.40 | 12.40 | 4.60 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 6.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 3.29 | 11.24 |
| Ws | 15.43 | 18.60 | 20.80 | 16.25 | 17.83 | 23.67 | 22.83 | 32.00 | 38.83 | 33.75 | 20.00 | 15.67 | 16.00 | 29.25 | 37.25 | 40.80 | 31.80 | 27.20 | 22.20 | 24.60 | 13.20 | 18.17 | 20.80 | 12.83 | 27.00 | 25.17 | 27.83 | 34.33 | 37.33 | 45.00 | 39.50 | 26.00 | 88.76 |
| n | 1.43 | 1.80 | 2.20 | 1.50 | 1.00 | 1.33 | 2.17 | 2.60 | 2.50 | 2.50 | 1.67 | 2.00 | 1.67 | 2.25 | 2.50 | 2.20 | 2.20 | 3.00 | 2.80 | 2.60 | 1.20 | 1.50 | 1.80 | 1.17 | 2.33 | 2.00 | 1.00 | 1.00 | 1.50 | 2.00 | 2.17 | 1.92 | 100 |
| A | 0.43 | 0.80 | 1.60 | 0.25 | 0.00 | 0.17 | 0.33 | 0.60 | 0.17 | 0.25 | 0.67 | 0.33 | 0.00 | 0.75 | 0.25 | 0.00 | 0.20 | 0.60 | 0.80 | 1.00 | 0.20 | 0.00 | 0.40 | 0.17 | 0.00 | 0.33 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.34 | 17.84 |
| B | 0.71 | 0.60 | 0.20 | 1.25 | 0.67 | 0.00 | 0.83 | 1.00 | 0.67 | 1.00 | 0.67 | 1.00 | 0.67 | 0.50 | 1.25 | 0.60 | 0.80 | 0.60 | 0.40 | 0.60 | 0.00 | 0.33 | 0.20 | 0.00 | 0.33 | 0.50 | 0.00 | 0.00 | 0.50 | 0.33 | 0.00 | 0.52 | 27.21 |
| C | 0.29 | 0.20 | 0.20 | 0.00 | 0.33 | 0.17 | 0.17 | 0.20 | 0.83 | 1.00 | 0.33 | 0.00 | 0.33 | 0.00 | 0.25 | 1.00 | 0.80 | 1.20 | 1.40 | 0.00 | 0.00 | 0.17 | 0.20 | 0.00 | 0.17 | 0.17 | 0.00 | 0.00 | 0.00 | 1.00 | 0.83 | 0.36 | 18.86 |
| D | 0.00 | 0.20 | 0.00 | 0.00 | 0.00 | 0.83 | 0.83 | 0.80 | 0.83 | 0.25 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.13 | 6.91 |
| E | 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 | 0.17 | 0.67 | 0.83 | 0.50 | 0.33 | 0.17 | 0.09 | 4.48 |
| 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 | 0.17 | 0.17 | 0.17 | 0.02 | 0.84 |
| G | 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 | 0.75 | 0.75 | 0.60 | 0.40 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 0.33 | 0.17 | 0.33 | 0.17 | 0.50 | 0.15 | 7.55 |
| 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 | 0.20 | 0.20 | 0.00 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.02 | 0.95 |
| I | 0.00 | 0.00 | 0.20 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.67 | 0.67 | 0.25 | 0.00 | 0.00 | 0.00 | 0.40 | 0.20 | 0.80 | 0.80 | 1.00 | 1.00 | 1.00 | 1.67 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.30 | 15.36 |
| x | 1.14 | 1.40 | 1.80 | 1.50 | 0.67 | 0.17 | 1.17 | 1.60 | 0.83 | 1.25 | 1.33 | 1.33 | 0.67 | 1.25 | 1.50 | 0.60 | 1.00 | 1.20 | 1.20 | 1.60 | 0.20 | 0.33 | 0.60 | 0.17 | 0.33 | 0.83 | 0.00 | 0.00 | 0.50 | 0.33 | 0.33 | 0.87 | 45.05 |
| r | 0.29 | 0.20 | 0.20 | 0.00 | 0.33 | 0.33 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.40 | 0.20 | 0.20 | 0.00 | 0.00 | 0.00 | 0.17 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.50 | 0.11 | 5.91 |
| s | 0.00 | 0.20 | 0.20 | 0.00 | 0.00 | 0.33 | 1.00 | 0.80 | 0.83 | 1.25 | 0.33 | 0.00 | 0.67 | 0.75 | 0.75 | 0.80 | 1.00 | 1.60 | 1.60 | 0.80 | 0.80 | 0.67 | 1.00 | 1.00 | 1.33 | 0.17 | 0.00 | 0.00 | 0.00 | 0.17 | 0.33 | 0.59 | 30.86 |
| a | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 0.00 | 0.20 | 0.67 | 0.00 | 0.00 | 0.67 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.00 | 0.00 | 0.50 | 0.33 | 0.00 | 0.00 | 0.00 | 0.17 | 0.00 | 0.11 | 5.65 |
| 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 | 0.33 | 0.25 | 0.25 | 0.40 | 0.00 | 0.00 | 0.00 | 0.20 | 0.20 | 0.00 | 0.00 | 0.00 | 0.17 | 0.50 | 0.50 | 0.17 | 0.00 | 0.50 | 0.67 | 0.13 | 6.94 |
| 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 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.50 | 0.83 | 1.00 | 0.50 | 0.33 | 0.11 | 5.59 |
| x | 0.43 | 0.80 | 1.80 | 0.25 | 0.00 | 0.33 | 0.33 | 0.60 | 0.17 | 0.25 | 0.67 | 1.00 | 0.67 | 1.00 | 0.25 | 0.00 | 0.20 | 1.00 | 1.00 | 2.00 | 1.20 | 1.00 | 1.40 | 1.17 | 1.83 | 0.50 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 0.66 | 34.15 |
| o | 1.00 | 1.00 | 0.40 | 1.25 | 1.00 | 0.83 | 1.67 | 1.80 | 2.33 | 2.25 | 1.00 | 1.00 | 1.00 | 1.25 | 2.25 | 2.20 | 2.00 | 2.00 | 1.80 | 0.60 | 0.00 | 0.50 | 0.40 | 0.00 | 0.50 | 1.33 | 0.33 | 0.17 | 0.83 | 1.17 | 1.33 | 1.14 | 59.08 |
| i | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.17 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.67 | 0.83 | 0.67 | 0.83 | 0.33 | 0.13 | 6.77 |
| 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 | 0.00 |
| CV | 3.29 | 8.00 | 5.00 | 2.75 | 3.00 | 20.00 | 24.83 | 24.20 | 27.00 | 19.50 | 5.67 | 7.00 | 21.67 | 29.75 | 31.25 | 35.40 | 20.00 | 22.80 | 19.00 | 18.20 | 16.20 | 10.50 | 11.80 | 10.17 | 24.33 | 40.33 | 49.00 | 47.50 | 47.17 | 52.00 | 54.17 | 22.95 | 100 |
| CVn | 0.29 | 0.40 | 0.60 | 0.50 | 0.00 | 0.00 | 2.00 | 1.60 | 0.00 | 0.25 | 0.33 | 1.33 | 0.67 | 0.00 | 0.00 | 0.00 | 0.60 | 6.00 | 5.00 | 0.60 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.83 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.68 | 2.95 |
| CVs | 3.00 | 7.60 | 4.40 | 2.25 | 3.00 | 20.00 | 22.83 | 22.60 | 27.00 | 19.25 | 5.33 | 5.67 | 21.00 | 29.75 | 31.25 | 35.40 | 19.40 | 16.80 | 14.00 | 17.60 | 16.20 | 10.50 | 11.80 | 10.17 | 24.33 | 39.50 | 49.00 | 47.50 | 47.17 | 52.00 | 54.17 | 22.27 | 97.05 |
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