Has Solar Cycle 24 finished?

Those who are daily active on the 12m and 10m band must have noticed that propagation was relatively good even excellent during the 3rd and 4th quarter of 2011. The bands, including 6m, were wide open for long range contacts. I observed long path QSO’s, “around the world trip” echoes daily. In a “normal” cycle you would see months with high and lower sunspot numbers and average solar flux, but with an increasing trend. This cycle does things different. In the last 5 months solar activity continued to decrease. The anticlimax was  this week when the background X-ray flux went below B-level, followed by a solar flux below 90. Does this mean that Cycle 24 passed it’s maximum?

Probably a few readers remind I did some predictions on the Solar Cycle 24 maximum, when I was doing a presentation at the VERON department Breda. I stated that SC24 maximum should be around mid 2011 and not in 2013 as predicted by NASA and SIDC. That prediction was based on the migration of sunspots from. At the start of a cycle, sunspots pop out at higher latitude on the sun’s surface and as the cycle proceeds sunspots pop out more closer to the sun’s equator. Sunspots tend to move or “migrate” towards the sun’s equator. When sunspots pop up near the equator, the cycle is nearing the end.

Based on the data of past months I believe the chance that Cycle 24 will produce a second peak like in 4th quarter 2011, is somewhat higher than the chance that Cycle 24 continues its descend to a new minimum.

But, there is a big BUT. Cycle 24 has surprised as many times before, for example the very steep ascend to the peak in Q4 2011. A new surprise, would not surprise me…

73 de PA9X Jean-Paul Suijs

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