Constitution of the Upper Atmosphere

Abstract

PRESENT conceptions of the physical and chemical constitution of the upper atmosphere were summarised in a most entertaining way by Dr. G. C. Simpson in the twenty-fourth Bedson lecture delivered at Armstrong College, Newcastle-upon-Tyne, on February 2. Dr. Simpson dealt first with the thickness of the troposphere over the earth's surface, and the temperature distribution within it, and throughout the stratosphere, including the discoveries of Lindemann and Dobson since 1920 from observations of meteors, also ozone concentration and distribution relative to (surface) atmospheric pressure. The evidence of sound wave and wireless wave reflections was then reviewed, and finally the evidence from auroral observations on the influence of sunlight, and on the composition of the atmosphere. Clouds in the stratosphere, and the dissociation of oxygen and nitrogen molecules at 100 km. and above were all touched upon. Throughout his lecture, Dr. Simpson stressed the uncertainty of prophecy in these matters, but his exception of weather forecasting caused amusement. Most of the learned societies of the district were represented in the audience, which was highly appreciative of the visit.