Marlins Anne Jones, age 12, of Fredericton,‑N. B., for her question:
How do sunspots affect radio?
A radio beam streams out from the broadcasting station in a straight linen. This means that it cannot bend around the curved surface of the earth. As the ground slopes away below it, the beam cuts upwards through the atmosphere. It travels up and up until it reaches the ionosphere, a layer of the earths atmosphere which begins about 60 miles above our heads.
The ionosphere is a region of thin air where the gas molecules, are few and far between. But, to a radio beam, this area is like a solid wall. It strikes and bounces back, down again towards the earth. It turns at an angle, thus striking the earth,ome distance from the broadcasting station. We say that radio beams are reflected back to the earth by the ionosphere. If they were not we could never send a radio message beyond the horizon.
The message, of course, is picked up by a receiving radio set. If all goes well, the message comes through smoothly just as it was sent from the broadcasting station. It arrives almost instantly. For the speed of the radio beam is the speed of light – 1,869,000 miles a second. But sometimes the message on the radio program is accompanied by crackles, gunfire and even strange wolf whistles. This interference is static.
The radio beam picks up most of this static in the ionosphere. At certain times this static is so bad that long distance radio breaks down altogether. Local radio and even TV may be upset. These periods of interference often correspond with sunspots, those mammoth electrical storms on the face of the sun,
This does not surprise us when we remember that radio waves are electro‑magnetic. And the ionosphere is named from its highly charged ions, or broken atomic particles. Add to these a stream of excited particles pouring from the sunspot. This bombardment makes the highly charged particles of the ionosphere still more agated. The floor of the ionosphere, normally used as the radio sounding board, is completely upset. The radio beams are not reflected smoothly back to earth.
Instead of a smooth radio program the sound is broken up with static. And this upset can be caused by streams of excited electrons; pouring out from a sunspot. When transatlantic telephone depended on radio, it often was impossible to talk across the ocean after a bad rash of sunspots. That is one reason why we now have a transatlantic telephone cable.
Sunspot activity also causes the beautiful auroras. Those same elecatron streams which upset radio excite the ions in the i. sphere enough to make them glow with ghostly colors. And, since TV also travels on electromagnetic waves' sunspot activity can add a little extra gunfire to a TV program.