SUNSPOTS AND RAIN

Dominion, Volume 37, Issue 18, 16 October 1943, Page 4

SUNSPOTS AND RAIN

Evidence Against A Theory

Pointingout that the exceptionally wet weather of the last few months has coincided with a period of comparatively little sunspot activity, a period that is apparently the low point in the sunspot cycle, Mr. G. V. Hudson, Karori, remarks that this does not bear out the theory that a light rainfall is associated with absence of sunspots. It seems niore probable, he says, that the rule is that extremes in solar phenomena (maxima and sunspot phases) may be connected with extremes in world weather. “During the whole of May and June there were very few sunspots, and those that did appear were all very small in size,” says Mr. Hudson. “In June there were four days when the solar disc was without spots. From July 1 to 7 inclusive' the sun was completely quiescent, and no spots were visible on Hie disc during that period. A further interval of four days without spots occurred on July 20, 22, 23 and 24. From July 25 till the end of August the spots were few in number and very small in size, and there were three days without spots. On September 1,2 and 3 there were no spots, but on September 8 a large and complex group was observed in the suns western hemisphere, about 70,000 milef. long and 30,000 miles wide. This group continued to increase in size till it passed round the western limb on September 12. It returned round the eastern limb on September 27 considerably reduced in size, and has been declining ever since. It is now on the far side of the sun.

“From these loeal observations we are probably justified iu assuming (iu the meantime) that the soliir minimum aecually occurred during the first week in July, 1043, subject, of course, to amendment, should later observations render an alteration necessary, llecently the Mpteecological Office reported that the w Islington rainfall during the last four mouths had been greatly in excess of the average and this period well covers that of the recent solar minimum. -the theory that a light rainfall is associated with the absence of sunspots is not borne out bv these local events and the idea. .uiit extremes in solar phenomena may be connectcd with extremes iu world weatuer seems more probable.”