The distribution of electricity in thunderclouds

Abstract

The mechanism of thunderstorms has been the subject of much controversy in recent years, and at the present time there are at least two theories which find considerable support. To arrive at a theory which would satisfy all criticism would be a great advance towards a solution of the more fundamental problem of the circulation of electricity through the atmosphere. The evidence put forward in support of the present theories of the mechanism of thunderstorms is derived almost wholly from observations made at the surface of the earth; in many cases this evidence is ambiguous, and the same observations have, in fact, sometimes been used to support opposing theories. It seemed highly desirable that fresh evidence should be sought, and the most promising line of attack appeared to lie in attempting measurements in and above the thunderclouds instead of confining the observations to ground-level. In 1934, after some preliminary experiments, a simple method of recording the distribution of electricity in thunderclouds by means of instruments attached to sounding balloons was devised at Kew Observatory, and a sufficient number of soundings has now been made to enable some important generalizations to be made. The method of observation and the results obtained are described and discussed in this paper.