GLORY OF THE STARS

New Zealand Herald, Volume LXXV, Issue 23002, 1 April 1938, Page 15

GLORY OF THE STARS

HEAVENS IN^APRIL SUNSPOTS AND WEATHER CONFUSING CORRELATIONS BY CKUX AUSTXIALXS While solar omissions have been proved to affect the Earth's magnetic phenomena markedly, unfortunately for the advancement of meteorology, attempts to correlate the variations in the number of sunspots with weather changes on our globe havo not met with tho same success. It is certain that tho Sun, with its vast outpouring of warmth, is a basic factor in meteorological phenomena, but temperatures, rainfall and humidity are so affected by a number of purely terrestrial factors that it has been almost impossible to determine any correlations whatsoever. For example, over the period 1902-1921 the water level of the great lakes in central Africa varied in harmony with the solar cycle, but the correspondence has now broken down, possibly owing to the deepening of a river that feeds the lakes. Growth of Tree Rings Another effect has been traced in the annual growth of treo rings. Tho astronomer Douglass, after an investigation of thousands of trees in Arizona, found a marked cycle in harmony with the rainfall there, and as tho rainiall in Arizona varied in sympathy with the solar cycle the connection between tree growth and sunspots was established. By further research, going back several centuries, Douglass found that between '1660 and 1720 the variations in the rings seemed to vanish. Three years later an English astronomer making an exhaustive study of past records found that there was a unique and prolonged dearth of spots between 1640 and 1715. U So great is the present faith in the evidence of tho tree rings that Douglass turned from astronomy to meteorology and thence to archaeology, dating the ruins of buildings loft by the Indian races from the evidence of tho trees they are built of.

The student of economics even encounters the influence of tho Sun, for Jevrons has attempted to show that the solar cycle is reflected in an 11year recurrence of slumps. Questions of Weather

When we turn to the more interesting questions of weather, however wo are met by instant confusion, while the rainfall in Arizona varies in sympathy with the number of sunspots there are other places where the curves are directly opposed. There appears to be a shift in storm tracks over the globe in sympathy with the solar cycle. Snowfall records show more snow at solar maximum than at minimum, while three times as many icebergs come from the polar regions at maximum than at minimum solar activity. In equatorial regions, and also in the temperate zones, temperatures are distinctly lower at sunspot maximum and higher at minimum, but further north and south in arid regions the reverse is actually the case. More hurricanes are encountered in the Atlantic at sunspot maximum, while in the South Pacific reverse conditions are indicated. In the chaos facing the investigators cyclic changes in harmony with the Sun have been predicted, all too freely, and enthusiasts have endeavoured even to trace every ill the world is heir to in the spottedness of tho Sun. Thus we hear of wars, famines, suicides and lunacy even being correlated with sunspot frequencies. Activity Unpredictable

Even if the astronomers were able to fix definite correlations between the solar cycle and terrestrial phenomena, the meteorologists would not be much better off as no one can predict in advance the future state of solar activity. The 11-year cycle that is commonly referred to as the period of sunspot activity varies in a most irregular manner. Tho maxima may occur only eight years apart, or in some cases they are separated by an interval twice as long At the best, if all the correlations had been soundly established, we mig.it venture to predict with reasonable accuracy the weather to rule a year ahead, but long-range forecasts ot greater length would be* almost as unreliable as they are in. the present state of our knowledge. Phenomena for April

The Sun will be in the constellation of Pisces until April 18, when it will pass into Aries. Its noon altitude at Auckland will decline during the month from 49 degrees to 38i degrees. The Moon will be in conjunction with the various naked-eye planets as follows: —Venus, 2nd, 11 a.m.; Mercuiy, 2nd, 6 p.m.; Mars, 3rd, 8 p.m.; Jupiter, 25th, 2 p.m.; baturn, 28th, jvfercury will attain its greatest elongation east of the Sun in the western "evening sky on April 2. lhereafter it will draw in towaru that orb, beinti in conjunction with it on the On the nights of the Bth and 9tli Mercury will lie close to the brilliant Venus, thereby making its identification easy. Mars also is in the evening sky at present', being visible on!y for a short while aftef sunset, Jupiter and baturn are both in the morning sky now, the former rising several! hours before sunrise and the latter being too near the Sun for observation.