MANY years ago, an otherwise eminent climatologist discovered that the level of the water in Lake Victoria, in Africa varied directly with the well-known sunspot cycle. That which had long been suspected he had thereby proved; there was a link between sunspots and the weather. But alas, it was not so. His study related to the years from 1890 to 1920, and within that period the rise and fall of the lake water did indeed match the 11-year sunspot cycle, but further research showed that outside these years, there appeared to be no relationship at all.
His experience was not unique. It is known that sunspot activity reflects a cyclical variation in the radiant energy of the sun, and for generations there have been continuing efforts to establish links between this varying solar output and events on Earth. Many researchers over the years have claimed to have found variations in rainfall or temperature that coincide with the sunspot cycle, but the connection is always tenuous and often, as we have seen, turns out to be ephemeral.
An August issue of The New Scientist reports yet another attempt to establish a link between sun-spots and the weather. Norman Lawrence has studied weather records, compiled over centuries, and claims that a peak in rainfall in Britain and Ireland regularly occurs about two years before each sunspot maximum.
A similar peak in rainfall, he asserts, occurs about two years before a sunspot minimum, and he has similarly identified regularly recurring periods of summer drought. Using this methodology, Lawrence has produced a forecast: he predicts increasing rainfall during the next few years, followed by, seasonal droughts at the next sunspot maximum somewhere around the year 2000.
A more flamboyant solar forecaster, however, is Piers Corbyn, an astrophysicist who runs a company called Weather Action, based at the South Bank University in London. Corbyn claims to be able to produce accurate forecasts of the weather in considerable detail up to three months ahead, using a method which he calls the "Solar Weather Technique". His precise methodology is a closely-guarded secret, but is apparently based on variations in the output of the sun in all its forms - electromagnetic radiation, particle emission and magnetic forces.
Corbyn reportedly predicts a White Christmas this year in many parts of Britain, and has a unique way of demonstrating his confidence. He is said to have placed substantial bets with a leading British book-maker that snow will fall on designated UK cities during Christmas Day this year.