WEATHER CYCLES

Timaru Herald, Volume CXLI, Issue 20308, 6 January 1936, Page 6

WEATHER CYCLES

RELATION TO SUN SPOTS The relationship between cycles of wet weather and “sun spots” was discussed by Sir James Jeans, the astronomer, in a lecture at the Royal Institution. These spots—any one of which is large enough to engulf the earth—are in reality “bubbles” of gas which rise from the boiling centre of the sun. When they reach the surface they burst and shoot off as jets of electrically charged particles eta speed which may rise to 300 miles a second, or over a million miles an hour. Sir James said that 30 hours after a spot was seen to be directly facing the earth we had a magnetic storm. These streams of particles come out of the sun like a shot from a gun and hit the earth.

The sun spots vary in number from year to year, but have a definite periodicity of eleven years, which coincide with the periodic waves of magnetic storms.

“They are responsible for all the magnetic weather,” said Sir James “and it seems likely that the sun spots also influence meteorological weather.

"There is a great deal of superstition about how far astronomical conditions affect weather—dry weather after the new moon, and so forth. The only astronomical phenomenon which influences weather, so far as we know, is the number of sun spots and the size of them.”

Sir James showed how over a number of years the height of the water in Lake Victoria rose in almost exact correspondence with the eleven-year peak periods of the sun spots, indicating an increased ramfall. Further evidence was being gathered by Professor Douglas, of the University of Arizona, who cut down innumerable trees and examined the age-rings in the trunks. At regular intervals there were especially thick rings, indicating a wet and hot year. It was possible to reconstruct the history of a country’s climate by this means.

Similar evidence was also being obtained by noting the regular intervals of certain geological deposits which resulted from increased rain. Sir James said that while the largest number of these spots had occurred every eleven years, they

were present nearly always, and could easily be seen through a piece of dark