Word: cyclic
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Dates: during 1980-1989
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...pointed the newly invented telescope at the sun and saw black spots on its surface. So much for solar purity. Despite clerical disapproval, the reality of sunspots was quickly accepted. Still, more than two centuries passed before Samuel Heinrich Schwabe, a German apothecary and amateur astronomer, discovered the strange, cyclic behavior of the solar blemishes...
...hypothetical planet Vulcan, supposedly the closest one to the sun, hoping to spot it in silhouette as it moved across the solar disk. In the process, he observed and kept meticulous records of sunspots over a 17-year period. Finally, in 1843, he recognized and announced the eleven-year cyclic nature of the spots and wrote, "I may compare myself to Saul, who went to seek his father's ass and found a Kingdom...
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...
...production was high and the sun apparently quiescent. But did this mean that all of these periods were times of extreme cold? Many scientists doubted it, suggesting that the correlation between the Maunder minimum and the little ice age might be nothing more than sheer coincidence. Changes in solar cyclic activity, the doubters argued, were not necessarily accompanied by variations in the sun's output of heat and light and probably did not affect terrestrial weather and climate...
...small a cyclic change able to have a noticeable effect on weather? Two scientists suspect it may. Karin Labitzke of Berlin's Free University and NCAR's Van Loon have discovered a relationship between the solar cycle and the stratospheric winds over the tropics. During a 28-month period, these winds reverse direction, blowing half the time from the east, the other half from the west, a phenomenon meteorologists call the QBO, or quasi-biennial oscillation. Depending on the direction of the QBO flow, Labitzke and Van Loon found, solar maximums and minimums seem linked to changes in air pressure...