Wireless Telegraphy and the Ionization in the Upper Atmosphere

Abstract

A non-mathematical survey is given of the theory of the upper atmosphere and the behavior of wireless waves. The new physics of the atmosphere based on heating by the sun, cooling at night, winds, gaseous diffusion, etc., the observations of the heights reached by wireless waves, the skip distances, ranges, polarization, etc., led to the conclusion that the ionization in the upper atmosphere was caused by the ultra-violet light of the sun and that the electron density had a maximum value of about 3×l0 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> at 190 km for summer noon. The calculated ionization agreed well with the wireless facts during the day but fell off too rapidly at night. Below the maximum the ionization was not known exactly. The diamagnetic theory of the diurnal variation in the earth's magnetism called for an ion density of about 5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> from about 150 to 190 km. The drift currents of the ions, due to the earth's gravitation and magnetism, causes the sunset longitude to be at a potential of about 2000 volts above that of the sunrise longitude. This voltage, combined with the earth's magnetic field, causes the ions and electrons to rise at night. They move up into regions of lower molecular density where their recombination is less. Their rate of loss at night is about right to agree with the wireless facts. It is pointed out that quantitative experiments with waves between 70 and 400 meters, of which there have been very few, might contribute valuable information about the ionization.