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NEWSCIENCENEWSCIENCENEWSCIENCE McMath-Pierce solar telescope near Whatever happens, notes opposed to a more typical 40,000- Tucson. He looks at a spectral line Hathaway, "the Sun is behaving in 50,000 spots in modern times. emitted by iron atoms in the Sun's an interesting way and I believe The Maunder Minimum coincided atmosphere. Sunspot magnetic we're about to learn something with the middle—and coldest part— ields cause the line to split in new". of the "Little Ice Age", during which wo—an effect called "Zeeman (Source: by Dr Tony Phillips, Europe and North America, and splitting", named after the Dutch Science@NASA, 3 September 2009, perhaps much of the rest of the physicist Pieter Zeeman who Ahttp://science.nasa.gov/headlines/ world, were subjected to bitterly discovered the phenomenon in the y2009/03sep_sunspots.htm) cold winters. 9th century. The size of the The lower solar activity during split reveals the intensity of the Maunder Minimum affected he magnetism. nA the amount of cosmic radiation Astronomers have been The Maunder Minimum reaching the Earth. measuring sunspot magnetic coincided with the middle—and One recently published paper ields in this general way for coldest part—of the "Little Ice (Vaquero et al., Solar Physics nearly a century, bu 207[2]:219) suggests that the " . . Livingston added a twist. Age p) during which Europe and Sun's rotation slowed in the While most researchers North America, and perhaps deep Maunder Minimum (1684). measure the splitting fe) much of the rest of the world Throughout the Little Ice Age, spectral lines in the visible . ? the world also experienced part of the Sun's spectrum, were subjected to bitterly heightened volcanic activity. Livingston decided to try an cold winters. Indeed, scientists have infrared spectral line. Infrared tentatively identified four ines are much more sensitive causes of the Little Ice Age: o the Zeeman effect and decreased solar activity, provide more accurate answers. | THEMAUNDER MINIMUM AND increased volcanic activity, internal Also, he dedicated himself to THE LITTLE ICE AGE variability of the climate system, measuring a large number of T. Maunder Minimum is the and anthropogenic influences. sunspots—more than 900 between name for the period roughly One of the difficulties in 1998 and 2005 alone. The spanning 1645 to 1715; it was used identifying the causes is the lack of combination of accuracy and _ by John A. Eddy in his landmark consensus on what constitutes numbers revealed the downturn. 1976 paper published in Science. It "normal" climate. If sunspots do go away, it wouldn't was a period when sunspots became (Sources: Wikipedia, "Maunder be the first time. In the 17th exceedingly rare, as noted by solar Minimum", http://en.wikipedia.org/wiki/ century, the Sun plunged into a 70- observers of the time. Astronomers Maunder_Minimum; Wikipedia, “Little Ice year period of spotlessness, known before Eddy had also named the Age”, http://en.wikipedia.org/wiki/Little_ as the Maunder Minimum, that still period after the solar astronomer Ice_Age) baffles scientists. The sunspot Edward W. drought began in 1645 and lasted Maunder until 1715. During that time, some (1851-1928), of the best astronomers in history who studied (e.g., Cassini) monitored the Sun how sunspot and failed to count more thanafew latitudes dozen sunspots per year compared change wit br to the usual thousands. time. "Whether [the current downturn During one is an omen of long-term sunspot 30-year period decline, analogous to the Maunder within the Minimum, remains to be seen,” Maunder Livingston and Penn caution ina Minimum, recent issue of Eos. "Other astronomers Po indications of solar activity suggest observed only . ; that sunspots must return in earnest about 50 Zeeman splitting of spectral lines from a strongly magne- within the next year." sunspots—as tised sunspot. Whatever happens, notes Hathaway, "the Sun is behaving in an interesting way and | believe we're about to learn something new". (Source: by Dr Tony Phillips, Science@NASA, 3 September 2009, http://science.nasa.gov/headlines/ y2009/03sep_sunspots.htm) coldest part—of the "Little Ice Age", during which Europe and North America, and perhaps much of the rest of the world, were subjected to bitterly cold winters. THE MAUNDER MINIMUM AND THE LITTLE ICE AGE T. Maunder Minimum is the name for the period roughly spanning 1645 to 1715; it was used by John A. Eddy in his landmark 1976 paper published in Science. It was a period when sunspots became exceedingly rare, as noted by solar observers of the time. Astronomers before Eddy had also named the period after the solar astronomer Edward W. ELawdla Ww. Maunder (1851-1928), who studied how sunspot latitudes change with time. During one 30-year period within the Maunder Minimum, astronomers observed only _ ; about 50 Zeeman splitting of spectral lines from a strongly magne- ticead cuncnat Zeeman splitting of spectral lines from a strongly magne- tised sunspot. sunspots—as NEXUS ¢ 47 _ The Maunder Minimum coincided with the middle—and OCTOBER - NOVEMBER 2009 www.nexusmagazine.com