A Study of Whistling Atmospherics. V. Dispersion

Abstract

The dispersion characteristics of whistlers recorded at Brisbane, Adelaide, and Hobart, mainly during the lGY, are examined. The dispersion recorded at each station shows a wide range of values. Diurnal (10-15 st) and annual variations (20-25 si) are observed and correlations between dispersion and F. critical frequency and dispersion and magnetic disturbance are discussed. No association between dispersion and sunspot number was detected. The position of the "ionospheric sources" of the whistlers is of prime importance as dispersion varies with geomagnetic latitude. Much of the variation in dispersion observed by individual stations is believed to be due to their being able to "see" ionospheric sources up to 100 away.