Feature Archives | Feedback

Frank's column hit a nerve and the responses we are receiving are proof of that. Read the comments as well as Franks' response.

The Sunspots are Coming

By Frank Greenhalgh

Loving the spots

My first introduction to "Sunspots" and "Solar Flares" came when I was ten years old, probably in June 1947. My father took me out on a clear night and pointed to the northern sky. He was pointing to bursts of light coming out of sky. Sort of like poorly defined or unfocused lights. "That" he said proudly "is the "Aurora Borealis or Northern Lights." He described it as magnetic storms that occur in the North Pole and can be seen all the way down in Long Island, NY. I was impressed, and to tell the truth, I never saw an Aurora Borealis again. I also did not know it was caused by "Sun Spots."

Eleven years later in 1958, I again met up with the sunspots. I was now twenty one years old, in the Navy and an active radio amateur. Suddenly my six meter, (50 MHz.), Gonset communicator transceiver, with only six watts output was able to reach out beyond the line of sight. I was able to talk to other amateurs in Mexico, Missouri, Florida, Illinois, Texas and just about anywhere in the US during "Sporadic E layer" openings. The reason, of course was sunspots. It turns out that 1958 was a banner year for sunspots and it had been labeled the "International Geophysical Year" ưa year with many experiments made during it.

I missed the sunspot peaks in 1969 and 1979 but caught up to it in 1990. At that time, I had prepared for it. I had a brand new 7-element tri band beam and a kilowatt of power on 14 and 28 MHz. For the first time in my life, I was able to experience the thrill of amateur radio with both excellent equipment and band conditions. I remember talking to 106 different countries in one weekend! Talking in the early evenings to amateurs in Japan was a new experience. Australians were on in the mornings. I had a schedule every Sunday morning with India. I was like a kid in a candy store. Then it ended suddenly, the day the sunspots died.

Well, here it comes again. The sunspot cycle will peak in the year 2000 -2001. When that happens watch out.

What are Sunspots

Sunspots are exactly what they are called, dark spots on the sun. Some are large enough to be seen by the naked eye (they look like daisies). They have been seen and reported since 1600. The spots are caused by strong magnetic fields on the sun, which apparently cool down the area where this magnetic activity is taking place. Typically the temperature of the surface of the sun is 5,800K, but where the spots are it is only 3,000K.

The sunspot number, which reflects the relative amount of sunspot activity on a given day is cyclical and varies over a 22-year period with the polarity of the magnetic fields reversing every 11 years. It is during the reversal period that the sunspot number and the effects of these forces are maximum. Thus, every eleven years we have a maximum of sunspot activity and effects. Before the Internet it was possible to get the latest number on the National Bureau of Standards radio stations at 5, 10 and 15 megahertz. The number is announced in Morse code at certain intervals. In the 1980s radio amateurs would post these numbers on packet radio bulletin boards. Today the easiest way is to go to the NASA sunspot web site at http://www.sunspotcycle.com . Sunspot numbers run from zero between peaks, to peaks of approximately 250. As I write this the number is 82, which is not very high. The web page also has a number of interesting articles and observations of the sun's behavior. One article there hypothesizes the effects sunspots have on our weather and states that it might be linked to the ice ages of the past. One web page (http://www.spaceweather.com/java/sunspot.html ) has a history graphic that allows you to input any date and see what the sunspot numbers were in that period. All in all the entire web site is very interesting with a ten day animation of the sun spots, and reports of many other effects and observations by scientists.

What to expect

We are presently in sunspot cycle number 23. The highest numbers in 1958-59 reached 250 at the apogee. In the year 2000, NASA is predicting a high of approximately 180. Not a banner year but who knows? During the periods of high sunspot activity, we can expect HF radio communication to change radically. If you have a radio capable of receiving short wave, you will be surprised to hear a great deal of activity on the frequencies of 10 to 30 MHz during daytime hours. This is because these frequencies which normally pass right through the "Ionosphere" or "Kennelly Heavyside Layer" now will bounce back to earth, due to the greater ionization of these layers.

Magnetic storms will also occur. They can cause different problems on earth and in the sky. A few years ago, a magnetic storm knocked out a power grid in the Western US. Magnetic storms also may knock out some communication and spy satellites. The greater proliferation of these birds certainly will increase the chances of this happening.

Stay Tuned

As these cycles only occur every eleven years, it means that you only get a few chances in a lifetime to experience them. Today, with the Internet sites keeping score, observing latest number and sun photos is easy enough. Low band TV, channels 2-6 should participate in "band openings" so if you still use an antenna for TV reception it might surprise you to see stations you never saw before. During the peak of the cycle it will be possible, with a small portable short wave radio to hear stations all around the world (10 to 30 megahertz). As the technology of the world changes possibly the HF radio bands will become obsolete by the next cycle. So don't miss this one.

Embedded Systems Home | Applications | Chips | Software | Boards | Embedded Java | Feature

		Click here to get your listing up.