METEOROLOGY

Hokitika Guardian, 24 December 1931, Page 3

METEOROLOGY

NEW LINE OF RESEARCH. OZONE CONTENT OF THE AIR. WELLINGTON, December 22. “It- will produce useful information and enabi'e us to understand atmospheric processes better and, perhaps, some day there will be a slight improvement in forecasting as a result of it.”

These Were the words used on his return to New Zealand to-day by Dr K. Kidson, Director of -Meteorological Services/when referring to the probable outcome of an extraordinary new line of research for which an instrument has just been developed by Dr G. M. V. •Dobson, lecturer in meteorology at Oxford University. .

Dr Dobson has been interested for some time in the correlation of the ozone content of the air with weather processes. He developed a few years ago a photographic instrument, of which copies were sent to various parts of the world for the. purpose of making observations of ithe sun with a view to determining the ozone content under different sky conditions. One of tile instruments, which are not unlike long cameras, was sent to Dr C. C. Farr at Canterbury College, who made a series of observations with it. The instrument of which Dr Kidson spoke to-day is a later development in connexion with the same line of research. It is referred to as a photo-electric spectrometer, or a spectrophotometer, and it has incorporated in it a- photo-electric cell made of calcium. “The solar radiation is measured in various parts by means of its action on the photo-electric cells,, said Dr Kidson explaining the new development. ►‘By -measuring the intensity of the radiation in two different portions of the ultra-violet end oi the spectrum, the observer is able to estimate th.? total amount of ozone in the atmosphere at any time. Just recently Dr Dobson has been able to extend his observations -to the period of moonlight, and estimate the amount of ozone at night time. Through being abie- to measure during both day and -night, they are ible to say that there is very little

tjurnal variation in the ozone content, it is found that there is a close rela'on between the distribution of ozone and pressure systems such as a cyclone juict an anti-cyclone. Just in the rear of the centre of a cyclone ozone is abnormally plentiful, whereas hi an .inti-cyclone it is comparatively little. “It has also been found,” Dr Kidsou went on to -say, “that-there is an • innual variation in the amount ot ozone. It is greatest in the winter and 'east in the summer. It has been discovered also that- 'the. ozone content is high over the Polar regions during the Polar night, while in equatorial, regions there is comparatively little. It looks, therefore,- as if the Polar regions were the chief source of atmospheric ozone. By means of -observations at various lines of the day -it is possible 'to get , rough -estimate of fll>e. height of the atmospheric layers m which Diozone occurs. The measurement of the amount of ozone at frequent intervals will -probably prove to he the means of determining atmospheric currents m the very high' levels.”