MYSTERIES OF THE AURORA.

Wanganui Chronicle, Volume 75, Issue 118, 21 May 1932, Page 1 (Supplement)

MYSTERIES OF THE AURORA.

A British scientific expedition will go to Tromso, Norway, this year, to investigate the ionized layers above the earth’s surface. When wireless telegraphy was first used, said Dr. C. G. Simpson, Director ,of the Meteorological Office, men of science were surprised to discover that the waves, unlike waves of light, followed the curvature of the earth’s surface. This meant that something in the upper atmosphere acted as a mirror and reflected them downward toward the earth. It was therefore concluded that the upper atmosphere was ionized. A few years ago Professor Appleton showed that this theory was accurate, and was able to fix the height of the mirror layer at something like 60 miles. This was just the height at which the aurora occurred, and they we bound to ame some con nee lion between the nuroa and the reflecting layer. Professor Appleton found tha with very short wave-lengths at certain times of the day the waves went through the first mirror and struck another at about 120 miles above the earth. The lower layer reflected the long waves and the upper layer the short ones. These mirrors must be made by tearing p the atoms and making them into electrical conductors. The lower layer was probably produced by the auroa, and the upper layer was supposed to be ionized by the ultra-violet rays coming from the sun. The only way to find out was to go to a place where the auroa i as frequently found and where there were no ultra-violet rays over the long p I of the Arctic winter, and to try to discover, by frequent measurements of the height and intensity of these mirrors, how they were made.