STUDIES ON THE VERTICALLY AND HORIZONTALLY POLARIZED COMPONENTS OF ATMOSPHERICS

Abstract

A lightning discharge is known to emit the electromagnetic radiations in the wide range of frequen-cies from a few hertz to beyond the visible region. The visible radiation is utilized in photographic and spectroscopic studies while radiations in the ELF and VLF regions can serve as a powerful tool in understanding the propagation characteristics of these waves. It is well established that the ELF and VLF waves have very low attenuation and high phase stability. By virtue of these properties they are widely used for reliable long range communication and navigation systems, location of thunderstorms, short term weather forecasting and to study the characteristics of the waveguide between the earth and the ionosphere. The electromagnetic radiation venerated by light-ning discharge propagates in all directions. A part of it in the VLF range propagates upwards through the ionosphere and magnetosphere and is trapped along the geomagnetic field lines and propagates between the con-jugate points of the magnetic field lines. It is known as whistler. The studies on whistlers have been found more appropriate in predicting the electron number density and temperature variation, plasma drift velotity and wave °article interaction in the upper atmosphere.