Thursday, August 31, 2006

Is Solar Cycle 24 Beginning?

From the ARRL website:

The recent appearance on the sun of two so-called "backward sunspots" may mean solar Cycle 23 is drawing to a close and Cycle 24 now is under way or soon will be. At least that's the thinking of some scientists. "We've been waiting for this," said Solar Physicist David Hathaway of the Marshall Space Flight Center in Huntsville, Alabama, after the first backward spot showed up. "

A backward sunspot is a sign that the next solar cycle is beginning." The term "backward" refers to the sunspots' magnetic polarity. One such sunspot appeared briefly July 31, then disappeared, but its significance was that its magnetic polarity was just the opposite of current Cycle 23 spots.

Another more robust spot, Sunspot 905, appeared earlier this month -- although it subsequently began to dissipate -- and some sungazers are saying Cycle 24 already has begun.

ARRL propagation guru Tad Cook, K7RA, has been a bit more cautious. "As time goes on, there will be more Cycle 24 spots and fewer Cycle 23 spots," he said in a recent "Solar Update." In any event, radio conditions will not improve any time soon but over a period of several years of the course of the 11-year cycle, perhaps peaking around 2010.

You can find more on this backward sunspot on the NASA Science website.