sabato 25 marzo 2017

The K7RA Solar Update

The Sun just finished an extended period (16 days) of zero sunspots. There were none on March 4, one visible on March 5, then none on March 6-20. Finally, one sunspot group appeared on March 21-23, with a sunspot number of 12 on all three days. 

A sunspot number of 12 does not mean there were 12 sunspots. Every group of sunspots counts as 10 points, and every sunspot within those groups counts for one point. Therefore, the minimum non-zero sunspot number is 11. So, for the past three days, there were two sunspots in one group.

From F.K. Janda, OK1HH, geomagnetic activity forecast for the period March 24-April 19, 2017

Geomagnetic field will be:
Quiet on March 25, April 8-9, 14-15
Mostly quiet on April 13, 19
Quiet to unsettled March 26-28, April 10, 12, 18
Quiet to active on March 24, 31, April 1-4, 6, 11, 17
Active to disturbed on March 29-30, April 5, 7, 16

Amplifications of the solar wind from coronal holes are expected on March 24, 30-31, April 1-4, (5-8,) 12-13. (14,) 16-20, Dates in parenthesis are less likely to have enhanced solar wind.