SUNSPOTS AND WEATHER

Greymouth Evening Star, 17 April 1937, Page 10

SUNSPOTS AND WEATHER

SCIENTISTS ARE STILL BAFFLED

One of the largest sunspots seen for some years is now apparent on the face of the sun, says P. Crosbie Morrison, M.Sc., of Australia, and experience has shown that in such circumstances severe electrical storms and interruptions to all kinds of electrical and telegraphic services may be expected.

Su’nspots attain a. maximum in size and frequency every 11 years, and l!i.’!7 is the eleventh year since the' last maximum. Special study is being directed to them, therefore, in the hope that this year may see the solution of one of the most persistent I mysteries of science. Not only electrical disturbances, but also the rei cent terrific storms in the United States, and queer weather in Australia, and in New Zealand, are probably attributable to this recurrence of “sunspot maximum.” One of the first strange discoveries [made with the newly-invented telescope more than 300 years ago was the presence of dark spots on the face of the sun. They appeared to be “blowholes” in the incandescent soltfr atmosphere, and three centuries of study have produced tantalising fiagments of additional information about them without revealing their 1 character completely. i ' Ercsh life was given to the study I .when Schwabe, of Dessau, an amateur [ observer, announced in 1813 that the' spots occurred in regular cycles and' not fortuitously. Individual spots may , persist, for only a dpy or two; others last for moie than a month, slowly crossing the face of the sun, disappearing at one edge, and reappearing ] I days later«at the opposite edge as phe sun rotates on its 1 axis; indeed, [it was by observation of sunspots [that the period of rotation of the sun Iwas first determined. But Schwabe, as a result of 18 'years of persevering observation, demonstrated that there are long periods when the sun is scarcely spotted ■til, till, and that at other times the spots’ are unusually numerous and I large. He showed, further, that these maximum and minimum phases of "spottedness" recurred every II ; years. < Here was a rhythm in Nature hilh- ( erto .unsuspected, and scientists set. i out. confidently to trace its source.

They have been on the trail ever since without success. The importance of their quest increased' a hundredfold when it was- discovered in 1851 that magnetic disturbances and electrical storms on the earth recurred in cycles identical with the sunspot cycle. Since then cycles of 11 years have been observed in the most strangely, assorted: occurrences. Auroras, thunderstorms, harvests, famines, financial booms, and depression have been seen to wax and wane more or less in accord with the waves of maximum and minimum spottiness of the sun. Large sunspots almost invariably cause “static” in wireless reception. The electro-magnetic character of these “blowholes” has been verified with ingenious instruments. Each spot is like a volcano, spurting jets of charged electrons into space, and even across the 93,000,000 miles of void into the upper atmosphere of the earth. It has been shown that the spots occur in pairs, one member corresponding to the north pole and the other to the south pole of a magnet. Still the mystery behind it all has not been revealed. *

Without doubt the 11 years’ cycle exists. Every new observation proves* lit. and sunspots have been studied 'persistently and continuously since Schwabe’s day. Delving back into -the past, the year 181(1 was a year ■of sunspot maximum, and it is iknown in the records of the world las "the year without a summer” — [the weather was thoroughly out of ‘joint. Also. 1872, very close to an[other maximum, is still the wettest iyear on record in Britain, and it was abnormally stormy throughout the

world. Less outstanding peculiarities of weather have been associated with almost all the other maxima. and now 1!)."7. another year of sunspot maximum, already passes into the records with disastrous floods in the United Htates. and weather disturb a.iict.s in almost till parts of the world. But, as soon as individual storms and individual spots an- studied the correlation breaks down and science is baffled. A large sunspot appears, large enough Io engulf half a dozen cirlhs side by side without touching il,s walls, it crosses the sun and fades away, leaving the whole earth tranquil. On other occasions fierce cleenical storms arise in the year of sunspot. maximum, while the face of the sun may’ be temporarily clear of spots.

Again large- spots and world-wide storms coincide perfectly or a tranquil earth faces an unblemished sun.

I Astronomers have decided that there, must be some deeper cause within the sun for both sunspots and for electro-magnetic storms and displays of the aurora. Observatories at stiitegic points round the, world are constantly engaged in research in solar physics in a concerted effort to unravel the mystery. The solar phvsics observatory at. Mt. Stromlo, in the, Federal Capital Territory, is

one of the important links in this chain. All are prepared for unusual activity, hoping that this year of sunspot maximum may reveal the vital clue to the problem.