TO MEASURE AIR GLOW

Press, Volume CVI, Issue 31086, 15 June 1966, Page 8

TO MEASURE AIR GLOW

Using a yard-wide searchlight reflector from Burnham Military Camp, control equipment modified by the university industrial development department, a £l6OO grant from the Department of Scientific and Industrial Research, and researchstudent labour, the University of Canterbury physics department will set up an air-glow photometer in Rarotonga next summer.

Under the direction of Mr Clifford Miles, an American specialist on optics now lecturing in the department,

equipment is now being assembled to give southern hemisphere readings matching Hawaii, the conjugate point of Rarotonga. Gathering the emissions from ionised oxygen layers 50 to 100 miles up which make “air glow,” the searchlight mirror and another to be built will slowly scan an area of sky about 20 by 20 degrees, pass the faint light through a lens to make it “parallel,” then pass it through a filter to remove other light interference, and record on film the red and green lines of the oxygen spectrum. The mirrors will have a glass cover, as in a search-

light, and this chamber will be temperature controlled to give stability within threetenths of one degree. It will be kept at about 100 degrees Fahrenheit so as not to be affected by the heat of Rarotonga.

Mr Miles said yesterday that he wished to correlate variations in brightness of air glow and also the red and green lines. There were diurnal and seasonal fluctuations, peaks in winter, and more could be expected with the passing of the Quiet Sun Year.

Many branches of science were interested in the phenomena of air glow, Mr Miles said, probably more so

in the faint emissions than in its more spectacular manifestation in the aurora.

The picture shows (left) Mr Miles inside the scanning equipment and (right) the big mirror reflecting parked vehicles in the left sector and his eyes in the right.