What a day! First a major storm whacks the west coast, now we have the official start of solar cycle 24.
Solar physicists have been waiting for the appearance of a reversed-polarity sunspot to signal the start of the next solar cycle. The signal for the start of a new cycle is sighting a particular kind of sunspot. That wait is over.
A magnetically reversed, high-latitude sunspot, dubbed as number 981, emerged on the surface of the sun today. Just a few months ago, an “All Quiet Alert” had been issued for the sun. This reversed polarity sunspot today marks the beginning of Solar Cycle 24 and the sun’s return back to Solar Maximum.
Solar Cycle 24 has been the subject of much speculation due to competing forecasts on whether it will be an highly active or a quiet low cycle. If it is a low cycle, it may very well be a test of validity for some CO2 based AGW theories. Only time will tell.
UPDATE: There have been some questions about solar cycle length, and “when does one cycle end and another begin or is there overlap”? Thanks to Joe D’Aleo of ICECAP, please see the graph below:
This from ESA may help everyone understand the transition:
With the next solar cycle this [sunspot magnetic] orientation is flipped in both hemispheres, as the Sun’s global magnetic field reverses its orientation.
As a new cycle begins, the number of sunspots with the reverse orientation will increase and the ones with the orientation of the old cycle will decrease in number. In the transition period they can both occur on the Sun, as the two cycles have no sharp boundary and overlap.
Russ Steele has some interesting information on the current state of knowledge and predicting the next solar cycle intensity at his Dalton Minimum Returns site.