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Geomagnetic activity in April 1947
Mean Ap17.7No. 217 of 1138
G1+ days7
G3+ days1
Max Ap10017 Apr 1947
Daily Ap
Daily max Kp
| Date | Max Kp | Ap | Level |
|---|---|---|---|
| 8 Apr 1947 | 6- | 16 | G2 |
| 9 Apr 1947 | 6- | 33 | G2 |
| 17 Apr 1947 | 9- | 100 | G5 |
| 18 Apr 1947 | 6o | 50 | G2 |
| 19 Apr 1947 | 5- | 25 | G1 |
| 20 Apr 1947 | 5o | 30 | G1 |
| 25 Apr 1947 | 5- | 10 | G1 |
Same month a year earlier
| Month | Mean Ap | G1+ | G3+ |
|---|---|---|---|
| April 1946 | 19.7 | 7 | 3 |
| April 1947 | 17.7 | 7 | 1 |
Dates and time slots are UTC. Kp is the 3-hourly planetary geomagnetic index (0–9); Ap is the daily average disturbance. G1–G5 follow the NOAA storm scale (Kp 5- and above counted as G1). Aurora visibility also depends on weather and location. The latest values are preliminary.
About this page
Mean Ap 17.7 in April 1947, No. 217 of 1138 months since 1932; 7 days reached G1 or higher.