Word: sunspots
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...Sunspots tend to travel in pairs or groups of opposite polarity, like the ends of horseshoe magnets poking through the solar surface. During one eleven- year cycle, as the blemishes traverse the face of the sun in an east-west direction, the leading spots of each group in the northern hemisphere will generally have positive polarity, the trailing spots negative. In the southern hemisphere, the leading spots will be negative. During the next cycle, the hemisphere polarities will reverse. On average, then, 22 years will pass between solar maximums of the same sunspot polarity. This suggests to many astronomers that...
Solar Max has undermined those arguments. A sensitive radiometer aboard the satellite has confirmed that between 1980 and 1986 average solar output declined one-tenth of 1%, then leveled off, and now has begun to climb. The finding strongly suggests that solar radiation varies with the sunspot cycle and that the solar constant is not that constant after...
Since the sun in myriad ways governs the very existence of all terrestrial life, the cyclic changes in the sunspot population have, ever since Schwabe, inspired speculation about their effect on solar radiation and, consequently, on the earth. Though the sun is a rather ordinary star, its vital statistics are breathtaking by earthly standards. Some 865,000 miles in diameter, it consists largely of hydrogen (72%) and helium (27%) and is 333,000 times as massive as the earth. Solar temperatures range from about 27 million degrees F* in the core, where 600 million tons of hydrogen are fused into...
Analyzing tree-ring data from 5,000-year-old living bristlecone pines and even older dead ones, Eddy reported in 1976 that their carbon-14 content seemed to vary in rhythm with sunspot numbers. When sunspots were rare, as they were during the Maunder minimum, the amount of carbon 14 in the tree rings increased markedly; when they were numerous, the amount decreased. The explanation: during the sun's more active periods, its magnetic field, which ordinarily deflects some cosmic rays away from the earth, expands and becomes an even greater barrier to the rays. As a result, less carbon...
...darker central portions of sunspots, or umbras, have the strongest magnetic fields; the lighter exteriors, or penumbras, the weaker fields. Occasionally, the penumbras of two sunspots of opposite polarity merge as they move past each other, putting the oppositely charged umbras in contact. The results are spectacular. "Because the umbras have opposite polarities, they attract each other," says the Marshall Center's Moore. "The closer they are together, the stronger the pull. Then, as they push past each other, it's like an earthquake fault slipping. In this case the stored energy is released in a flare." In the sunspot...