SOLAR on cycle 24

In October 2006 NASA launched the Solar TErrestrial RElations Observatory (STEREO), part of the NASA Solar Terrestrial Probes program. STEREO is a two-year mission that uses two nearly identical satellites - one ahead of Earth in its orbit, the other trailing behind - to provide the first-ever three dimensional observations to study both the Sun and its coronal mass ejections. Of particular interest to amateurs, however, is that SOLAR's unique perspective allows astronomers to detect sunspots before they're visible here on earth. And we all know that as sunspots increase, so too does propagation.

So what is SOLAR telling us? According to the ARRL, sunspot numbers for September 17 through 23 were 0, 0, 0, 0, 11, 26 and 31, with a mean of 9.7. So is this the beginning of the long awaited solar cycle 24? Perhaps not. The Solar Cycle 24 Prediction Panel at NASA now agrees that the last solar minimum occurred in December, 2008, but in the words of the panel the next cycle is shaping up to be "the lowest of any cycle since 1928."

"In our professional careers, we've never seen anything quite like it," says Dave Pesnell from the Goddard Space Flight Center and NASA's lead representative on the panel. "Solar minimum has lasted far beyond the date we predicted in 2007."

Right now the prediction is that solar cycle 24 will peak in May 2013 with a below-average number of sunspots, providing only modest propagaton enhancement.

What's a ham to do? My suggestion -- tune up the antenna, invest in a beam, levage gray line propagation, enjoy the hobby, and let the sun take care of itself.

-73

-Steve KB3IHX

Of sunspots and Stradivarius

Amateur radio operators watch the latest sunspot reports much like investors watch Wall Street tickers. Are we coming out of the bottom of the lastest cycle? Are there signs of new spots on the solar disk?

As we all know, sunspot activity has a major effect on long distance radio communications. As sunspot activity increases, so too does propagation on shortwave frequencies. Sunspot cycles last about 11 years, and we're currently at the bottom of Cycle 23. But as many have noted, Cycle 24 seems to be slow in starting, leading to concerns that we may be entering another Maunder Minimum.

The Maunder Minimum (aproximately 1645 to 1715) was a period of exceptionally low sunspot activity. Whether a direct correlation exists between sunspots and global temperature is open for debate, we do know that this period corresponded to what became known as the "Little Ice Age" during which record low temperatures were experienced across North America and Europe. We also know that the variation in cosmic radiation bombarding the earth was affected, and this was reflected in the amount of carbon-14 found in tree rings. It's hypothesized that the colder temperatures led to slower tree growth, resulting in a very hard wood that Stradivarius used to such great advantage in crafting his incomparable violins.

Similar periods of extended solar minimums have been observed or indirectly detected via carbon-14 dating from 1450 to 1540, and again from 1790 to 1820. In fact, over the past 8,000 years the sun has spent about a quarter of its time generating few or no sunspots.

Nonetheless, scientists at the National Solar Observatory in Tucson, Arizona say the solar mechanism that generates sunspots is functioning just fine, albeit more slowly than usual. According to these scientists, the solar jet stream has reached the 'critical' latitude, and the number of observable sunspots is already on the rise. If this proves true then we can expect to see marked improvement in propagation from 20 meters all the way up through 6 meters nearly any time of day.

And that's music to my ears.

73
Steve KB3IHX