The Ultra-Violet Light of the Sun as the Origin of Auroræ and Magnetic Storms

Abstract

A THEORETICAL investigation has been made of the outlying regions of the atmosphere of the earth and of the effect of sunlight on these regions; certain of the conclusions are given in this preliminary note. By the usual methods the temperatures and the pressures of the atmosphere to great heights were calculated for a quiet sun, that is, the sun in its normal state, with no terrestrial auroræ or magnetic storms. Because of the unequal balance at cold temperatures between the solar energy absorbed in the ultra-violet by the atmospheric gases and the energy re-emitted in the infra-red by the gases, the daytime temperatures above 100 km. were found to increase with the height above the surface of the earth, until at 300 km. or 400 km. temperatures of 1000° Kelvin seem reasonable. (There is, of course, nothing novel in this, although we have been interested in working the matter out more exactly perhaps than has been done heretofore.)