Word: solarity
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Dates: during 1980-1989
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Most explanations of that phenomenon liken the sun to a dynamo. Mighty currents of electricity flowing in the solar interior generate magnetic-field lines that, like the earth's, tend to be oriented in a north-south direction. But because the sun, unlike the earth, is gaseous, it does not rotate uniformly: bands of gases around the equator circle the solar axis once every 27 days, compared with a 34-day rotation rate near the poles...
...pure statistics," Van Loon concedes. "We have no physical explanation for what we've found." That explanation may be hard to come by. Experts have calculated that the tiny change in the solar constant detected by Solar Max can supply less than a millionth of the energy needed to produce the observed changes in weather. "If there really is an effect," says Van Loon, "there must be an enhancing mechanism, and we don't have the foggiest idea of what that enhancing mechanism might be." Yet the statistical evidence is so compelling that many scientists are taking it seriously...
While astronomers who study the sun get more attention during periods of solar maximums, they generally feel somewhat neglected, underfunded and unappreciated, poor cousins to those who observe distant stars and galaxies in the night skies and who consider the sun boring. Then why do solar astronomers persist? "We are driven to an understanding of the sun," says Robert Howard, an astronomer at the National Solar Observatory in Tucson. "It is an enormous lab. It is a Rosetta stone for the study of the stars. With other stars, all you have is a pinpoint of light. By understanding more about...
...Leighton, "if the sun didn't have a magnetic field, it would be as dull as most nighttime astronomers think it is." What a difference a field makes. Twisted and stretched by both the sun's rotation and its roiling interior, the magnetic lines of force orchestrate the intriguing solar cycle...
...same time, hot gases, being lighter, rise from the interior to the surface, while cooler, heavier gases descend -- a process called convection (similar to what occurs in a hot oven). As a result of these massive convection currents and the differing rates of solar rotation, the magnetic lines of force begin wrapping around the sun like ropes. The wrapping action stretches the ropes and creates magnetic fields so strong that they repel the surrounding solar gases. In effect, this makes the magnetic regions lighter than the gases, and they begin to rise. Some reach the surface and become sunspots, dark...